arm64: dts: mediatek: mt7988a: add 'soc-uuid' cell to efuse

arm64: dts: mediatek: mt7988a: add 'soc-uuid' cell to efuse

The efuse of the MediaTek MT7988 contains a 16-byte unique identifier.
Add a 'soc-uuid' cell covering those 16 bytes to the nvmem defininition
of the efuse to allow easy access from userspace, eg. to generate a
persistent random MAC address on boards like the BananaPi R4 which
doesn't have any factory-assigned addresses.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>