configs: sama5d3xek: add default config for CMP board

configs: sama5d3xek: add default config for CMP board

The sama5d36ek CMP board is the variant of sama5d3xek board.
It is equipped with the low-power DDR2 SDRAM, PMIC ACT8865, and
some power rails. The board is mainly used to measure the power
consumption. As all those changes are done in at91bootstrap,
in U-Boot, only use another device tree file, no code needed
to change.

As there is additional power consumption when enbling the USB
Host and USB device, for the power consumption measurement
intention, disable the USB host and device.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>