Add LCDC device node in DT for am33xx
Add LCDC and Panel info in DT for am335x-evm

Changes:
- remove redundant/unnecessary SoC specific setting in the board dts
- resolved conflicts on for_3.13/dts
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Benoit Cousson <bcousson@baylibre.com>