arm64: defconfig: Enable Maxim MAX96712 Quad GMSL2 Deserializer support

Increase build and test coverage by enabling modular support for the
Maxim MAX96712 Quad GMSL2 Deserializer, as used on the Renesas Falcon
board.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/7b5ea7eaabc1da79fd974f9d9845a5a527f2fb14.1649947458.git.geert+renesas@glider.be