MAINTAINERS: update arm,pl353-smc.yaml reference

The file name: Documentation/devicetree/bindings/mtd/arm,pl353-smc.yaml
should be, instead: Documentation/devicetree/bindings/memory-controllers/arm,pl353-smc.yaml.

Update its cross-reference accordingly.

Fixes: 813d5279 ("MAINTAINERS: Add PL353 SMC entry")
Fixes: d3d0e1e8 ("dt-binding: memory: pl353-smc: Convert to yaml")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1a9b26e4f9f7a01bcd676d7e7a3a929085fc2adb.1626947923.git.mchehab+huawei@kernel.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>