ARM: dts: Add support for dra718-evm

ARM: dts: Add support for dra718-evm

The DRA718-evm is a board based on TI's DRA718 processor targeting
BOM-optimized entry infotainment systems and is a reduced pin and
software compatible derivative of the DRA72 ES2.0 processor.
This platform features:
- 2GB of DDR3L
- Dual 1Gbps Ethernet
- HDMI,
- uSD
- 8GB eMMC
- CAN
- PCIe
- USB3.0
- Video Input Port
- LP873x PMIC

More information can be found here[1].

Adding support for this board while reusing the data available in
dra72-evm-common.dtsi.

[1] http://www.ti.com/product/dra718

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>