linux-mchp: use yocto defconfigs for sam9x60 and sama5 platforms
linux-mchp: use yocto defconfigs for sam9x60 and sama5 platforms

SAM9x60 and SAMA5 platforms have separate kernel defconfigs. Add them in
SRC_URI to use them.

Signed-off-by: Codrin Ciubotariu <97034fe81dd68ee5e1fa3aa6216f6373b034daef@microchip.com>

linux4sam/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel