drm/imx/lcdc: Implement DRM driver for imx25

Add support for the LCD Controller found on i.MX21 and i.MX25.

It targets to be a drop in replacement for the imx-fb driver.

[ukl: Rebase to a newer kernel version, various smaller fixes and
improvements]
Signed-off-by: Marian Cichy <m.cichy@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230306115249.2223042-2-u.kleine-koenig@pengutronix.deSigned-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230306115249.2223042-3-u.kleine-koenig@pengutronix.de

drivers/gpu/drm/imx/Kconfig

@@ -2,3 +2,4 @@
 
 source "drivers/gpu/drm/imx/dcss/Kconfig"
 source "drivers/gpu/drm/imx/ipuv3/Kconfig"
+source "drivers/gpu/drm/imx/lcdc/Kconfig"

drivers/gpu/drm/imx/Makefile

@@ -2,3 +2,4 @@
 
 obj-$(CONFIG_DRM_IMX_DCSS) += dcss/
 obj-$(CONFIG_DRM_IMX) += ipuv3/
+obj-$(CONFIG_DRM_IMX_LCDC) += lcdc/

drivers/gpu/drm/imx/lcdc/Kconfig

+config DRM_IMX_LCDC
+      tristate "Freescale i.MX LCDC displays"
+      depends on DRM && (ARCH_MXC || COMPILE_TEST)
+      select DRM_GEM_DMA_HELPER
+      select DRM_KMS_HELPER
+      help
+        Found on i.MX1, i.MX21, i.MX25 and i.MX27.

drivers/gpu/drm/imx/lcdc/Makefile

+obj-$(CONFIG_DRM_IMX_LCDC) += imx-lcdc.o