ARM: dts: rockchip: add eDP panel support for Firefly

ARM: dts: rockchip: add eDP panel support for Firefly

This patch adds the supporting to the eDP panel sold by
the T-CHIP for the Firefly RK3288. I assign the VOP lite
for the eDP panel and VOP big to HDMI, as the HDMI supports
4K resolution. With a different VOP device, eDP panel
and HDMI could display a different contents.

The InvenSense MPU6050 sensor at the botton of the panel
is also enabled.

The Firefly RK3288 Reload use a different GPIO pin to enable
the power of the eDP panel.

Change-Id: Id78249f001d171ede79fe835d24c40a75ff8a0df
Signed-off-by: Randy Li <ayaka@soulik.info>
Signed-off-by: Randy Li <randy.li@rock-chips.com>