drm/panel: add panel driver for Leadtek LTK050H3146W

The LTK050H3146W is 5.0" 720x1280 DSI display. There are two variants
with essentially the same name, LTK050H3146W and LTK050H3146W-A2.

They differ in their init sequence and mode details.

changes in v2:
- add display variants
changes in v3:
- fixed indentation and artifacts found by Sam
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200408085317.2624599-2-heiko@sntech.de

drivers/gpu/drm/panel/Kconfig

@@ -137,6 +137,17 @@ config DRM_PANEL_KINGDISPLAY_KD097D04
 	  24 bit RGB per pixel. It provides a MIPI DSI interface to
 	  the host and has a built-in LED backlight.
 
+config DRM_PANEL_LEADTEK_LTK050H3146W
+	tristate "Leadtek LTK050H3146W panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for Leadtek LTK050H3146W
+	  TFT-LCD modules. The panel has a 720x1280 resolution and uses
+	  24 bit RGB per pixel. It provides a MIPI DSI interface to
+	  the host and has a built-in LED backlight.
+
 config DRM_PANEL_LEADTEK_LTK500HD1829
 	tristate "Leadtek LTK500HD1829 panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
+obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK050H3146W) += panel-leadtek-ltk050h3146w.o
 obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK500HD1829) += panel-leadtek-ltk500hd1829.o
 obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o