drm/bridge: add it6505 driver

This adds support for the iTE IT6505.
This device can convert DPI signal to DP output.

From: Allen Chen <allen.chen@ite.com.tw>
Tested-by: Hsin-yi Wang <hsinyi@chromium.org>
Signed-off-by: Hermes Wu <hermes.wu@ite.com.tw>
Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114091502.333083-1-allen.chen@ite.com.tw

drivers/gpu/drm/bridge/Kconfig

@@ -75,6 +75,14 @@ config DRM_DISPLAY_CONNECTOR
 	  on ARM-based platforms. Saying Y here when this driver is not needed
 	  will not cause any issue.
 
+config DRM_ITE_IT6505
+        tristate "ITE IT6505 DisplayPort bridge"
+        depends on OF
+        select DRM_KMS_HELPER
+        select EXTCON
+        help
+          ITE IT6505 DisplayPort bridge chip driver.
+
 config DRM_LONTIUM_LT8912B
 	tristate "Lontium LT8912B DSI/HDMI bridge"
 	depends on OF

drivers/gpu/drm/bridge/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o
 obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
 obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o
 obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
+obj-$(CONFIG_DRM_ITE_IT6505) += ite-it6505.o
 obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o
 obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
 obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o