MAINTAINERS: update ovti,ov2680.yaml reference

The file name: Documentation/devicetree/bindings/media/i2c/ov2680.yaml
should be, instead: Documentation/devicetree/bindings/media/i2c/ovti,ov2680.yaml.

Update its cross-reference accordingly.

Fixes: 57226cd8 ("media: dt-bindings: ov2680: convert bindings to yaml")
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>