drm/mediatek: Add DSI sub driver

This patch add a drm encoder/connector driver for the MIPI DSI function
block of the Mediatek display subsystem and a phy driver for the MIPI TX
D-PHY control module.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/mediatek/Makefile

@@ -6,6 +6,8 @@ mediatek-drm-y := mtk_disp_ovl.o \
 		  mtk_drm_drv.o \
 		  mtk_drm_fb.o \
 		  mtk_drm_gem.o \
-		  mtk_drm_plane.o
+		  mtk_drm_plane.o \
+		  mtk_dsi.o \
+		  mtk_mipi_tx.o
 
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o