drm: rockchip: dp: add rockchip platform dp driver

Rockchip have three clocks for dp controller, we leave pclk_edp
to analogix_dp driver control, and keep the sclk_edp_24m and
sclk_edp in platform driver.

Acked-by: Mark Yao <mark.yao@rock-chips.com>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

drivers/gpu/drm/rockchip/Makefile

@@ -6,6 +6,7 @@ rockchipdrm-y := rockchip_drm_drv.o rockchip_drm_fb.o \
 		rockchip_drm_gem.o rockchip_drm_vop.o
 rockchipdrm-$(CONFIG_DRM_FBDEV_EMULATION) += rockchip_drm_fbdev.o
 
+obj-$(CONFIG_ROCKCHIP_ANALOGIX_DP) += analogix_dp-rockchip.o
 obj-$(CONFIG_ROCKCHIP_DW_HDMI) += dw_hdmi-rockchip.o
 obj-$(CONFIG_ROCKCHIP_DW_MIPI_DSI) += dw-mipi-dsi.o
 obj-$(CONFIG_ROCKCHIP_INNO_HDMI) += inno_hdmi.o