drm: Add Drm driver for Rockchip Socs

This patch is a DRM Driver for Rockchip Socs, driver provides an abstraction
for the graphics hardware, such as lcd controller and display interface.

Signed-off-by: mark <mark.yao@rock-chips.com>
dt-bindings: add Documentation for rockchip lcd controller

Signed-off-by: mark <mark.yao@rock-chips.com>
drm: add rockchip lcd controller support

Signed-off-by: mark <mark.yao@rock-chips.com>
dt-bindings: add Documentation for rockchip display interface

Signed-off-by: mark <mark.yao@rock-chips.com>
drm: add rockchip lvds display interface

Signed-off-by: mark <mark.yao@rock-chips.com>
drm: fix rockchip drm for kernel 3.14
gpu: support gpu