drm: rockchip: introduce rk3066 hdmi

The RK3066 HDMI TX serves as interface between a LCD Controller and
a HDMI bus. A HDMI TX consists of one HDMI transmitter controller and
one HDMI transmitter PHY. The interface has three (3) 8-bit data channels
which can be configured for a number of bus widths (8/10/12/16/20/24-bit)
and different video formats (RGB, YCbCr).

Features:
HDMI version 1.4a, HDCP revision 1.4 and
DVI version 1.0 compliant transmitter.
Supports DTV resolutions from 480i to 1080i/p HD.
Master I2C interface for a DDC connection.
HDMI TX supports multiple power save modes.
The HDMI TX input can switch between LCDC0 and LCDC1.
(Sound support is not included in this patch)

Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190330095639.14626-2-jbx6244@gmail.com

drivers/gpu/drm/rockchip/Kconfig

@@ -77,4 +77,12 @@ config ROCKCHIP_RGB
 	  Some Rockchip CRTCs, like rv1108, can directly output parallel
 	  and serial RGB format to panel or connect to a conversion chip.
 	  say Y to enable its driver.
+
+config ROCKCHIP_RK3066_HDMI
+	bool "Rockchip specific extensions for RK3066 HDMI"
+	depends on DRM_ROCKCHIP
+	help
+	  This selects support for Rockchip SoC specific extensions
+	  for the RK3066 HDMI driver. If you want to enable
+	  HDMI on RK3066 based SoC, you should select this option.
 endif