media: MAINTAINERS: rectify entry in SAA7146 VIDEO4LINUX-2 DRIVER

Commit e33fdb5a ("media: saa7146: deprecate hexium_gemini/orion, mxb
and ttpci") moves some media drivers to the staging subsystem, and
unfortunately only partially adjusts the entry in MAINTAINERS.

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

As the files matching include/media/drv-intf/saa7146* are moved to
drivers/staging/media/deprecated/saa7146/common, this directory is already
covered by the existing file entry
drivers/staging/media/deprecated/saa7146/.

Repair this file reference in SAA7146 VIDEO4LINUX-2 DRIVER.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>