arm64: defconfig: Enable UBIFS

UBIFS is a file system for flash devices which works on top of UBI.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230417092243.967871-1-d-gole@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>