drm/rockchip: fix Kconfig dependencies

A bug that I had fixed earlier just came back, with CONFIG_EXTCON=m,
the rockchip drm driver will fail to link:

drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_get_port_lanes':
cdn-dp-core.c:(.text.cdn_dp_get_port_lanes+0x30): undefined reference to `extcon_get_state'
cdn-dp-core.c:(.text.cdn_dp_get_port_lanes+0x6c): undefined reference to `extcon_get_property'
drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_check_sink_connection':
cdn-dp-core.c:(.text.cdn_dp_check_sink_connection+0x80): undefined reference to `extcon_get_state'
drivers/gpu/drm/rockchip/cdn-dp-core.o: In function `cdn_dp_enable':
cdn-dp-core.c:(.text.cdn_dp_enable+0x748): undefined reference to `extcon_get_property'

The problem is that that the sub-drivers are now all linked into the
main rockchip drm module, which breaks all the Kconfig dependencies
that are specified in the options for those sub-drivers.

This clarifies the dependency to ensure that we can only turn on the DP
driver when EXTCON is reachable. As the 'select' statements can now
cause additional options to become built-in when they should be
loadable modules, I'm moving those into the main driver config option.
The dependency on DRM_ROCKCHIP can be reduced into a single 'if'
statement here for brevity, but this has no functional effect.

Fixes: b6705157 ("drm/rockchip: add extcon dependency for DP")
Fixes: 8820b68b ("drm/rockchip: Refactor the component match logic.")
Link: https://patchwork.kernel.org/patch/9648761/Acked-by: Guenter Roeck <groeck@chromium.org>
Tested-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170721211214.3386387-1-arnd@arndb.de

drivers/gpu/drm/rockchip/Kconfig

@@ -5,6 +5,10 @@ config DRM_ROCKCHIP
 	select DRM_KMS_HELPER
 	select DRM_PANEL
 	select VIDEOMODE_HELPERS
+	select DRM_ANALOGIX_DP if ROCKCHIP_ANALOGIX_DP
+	select DRM_DW_HDMI if ROCKCHIP_DW_HDMI
+	select DRM_MIPI_DSI if ROCKCHIP_DW_MIPI_DSI
+	select SND_SOC_HDMI_CODEC if ROCKCHIP_CDN_DP && SND_SOC
 	help
 	  Choose this option if you have a Rockchip soc chipset.
 	  This driver provides kernel mode setting and buffer
@@ -12,10 +16,10 @@ config DRM_ROCKCHIP
 	  2D or 3D acceleration; acceleration is performed by other
 	  IP found on the SoC.
 
+if DRM_ROCKCHIP
+
 config ROCKCHIP_ANALOGIX_DP
 	bool "Rockchip specific extensions for Analogix DP driver"
-	depends on DRM_ROCKCHIP
-	select DRM_ANALOGIX_DP
 	help
 	  This selects support for Rockchip SoC specific extensions
 	  for the Analogix Core DP driver. If you want to enable DP
@@ -23,9 +27,7 @@ config ROCKCHIP_ANALOGIX_DP
 
 config ROCKCHIP_CDN_DP
         bool "Rockchip cdn DP"
-        depends on DRM_ROCKCHIP
-	depends on EXTCON
-	select SND_SOC_HDMI_CODEC if SND_SOC
+	depends on EXTCON=y || (EXTCON=m && DRM_ROCKCHIP=m)
         help
 	  This selects support for Rockchip SoC specific extensions
 	  for the cdn DP driver. If you want to enable Dp on
@@ -34,8 +36,6 @@ config ROCKCHIP_CDN_DP
 
 config ROCKCHIP_DW_HDMI
         bool "Rockchip specific extensions for Synopsys DW HDMI"
-        depends on DRM_ROCKCHIP
-        select DRM_DW_HDMI
         help
 	  This selects support for Rockchip SoC specific extensions
 	  for the Synopsys DesignWare HDMI driver. If you want to
@@ -44,8 +44,6 @@ config ROCKCHIP_DW_HDMI
 
 config ROCKCHIP_DW_MIPI_DSI
 	bool "Rockchip specific extensions for Synopsys DW MIPI DSI"
-	depends on DRM_ROCKCHIP
-	select DRM_MIPI_DSI
 	help
 	 This selects support for Rockchip SoC specific extensions
 	 for the Synopsys DesignWare HDMI driver. If you want to
@@ -54,8 +52,9 @@ config ROCKCHIP_DW_MIPI_DSI
 
 config ROCKCHIP_INNO_HDMI
 	bool "Rockchip specific extensions for Innosilicon HDMI"
-	depends on DRM_ROCKCHIP
 	help
 	  This selects support for Rockchip SoC specific extensions
 	  for the Innosilicon HDMI driver. If you want to enable
 	  HDMI on RK3036 based SoC, you should select this option.
+
+endif