rcar-gen3: machine: Update KERNEL_DEVICETREE for M3ULCB
rcar-gen3: machine: Update KERNEL_DEVICETREE for M3ULCB

This commit updates machine configuration to add "r8a77961-ulcb.dtb"
for M3ULCB.

Signed-off-by: Khang Nguyen <8dfb9c771c579920706fa8a68e7ba00c68a28f22@renesas.com>
Change-Id: I84d95c1ecbbf20335d8e4f1c8faae7870715df70

renesas-rcar/meta-renesas,renesas-rcar/meta-renesas,renesas-rcar/meta-renesas,renesas-rcar/meta-renesas