MAINTAINERS: rectify entry for MESON NAND controller bindings

Commit fbc00b5e ("dt-bindings: nand: meson: convert txt to yaml")
converts amlogic,meson-nand.txt to yaml, but misses to adjust its reference
in MAINTAINERS.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a
broken reference.

Repair this file reference in MESON NAND CONTROLLER DRIVER FOR AMLOGIC
SOCS.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220929123431.23180-1-lukas.bulwahn@gmail.com