ARM: dts: Add support for dra76-evm

dra76-evm is a board based on TI's dra76 processor targeting
for infotainment systems. Adding support for this platform.

dra76-evm and dra7-evm has a similar layout except with few differences.
So create a dra7-evm-common.dtsi with similarities on dra76-evm and
dra7-evm. Include this common dtsi in both dra7-evm.dts and dra76-evm.dts

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>