MAINTAINERS: update st,vl53l0x.yaml reference

Changeset b4be8bd1 ("dt-bindings:iio:proximity:st,vl53l0x yaml conversion")
renamed: Documentation/devicetree/bindings/iio/proximity/vl53l0x.txt
to: Documentation/devicetree/bindings/iio/proximity/st,vl53l0x.yaml.

Update its cross-reference accordingly.

Fixes: b4be8bd1 ("dt-bindings:iio:proximity:st,vl53l0x yaml conversion")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>