media: MAINTAINERS: Make Tomasz the main maintainer of videobuf2

Tomasz is the most active member from the people listed currently in the
MAINTAINERS file, but is currently listed as a reviewer. Change the
entry into a maintainer and move to the top of the list.

Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

MAINTAINERS

@@ -18297,10 +18297,10 @@ S:	Maintained
 F:	drivers/media/platform/video-mux.c
 
 VIDEOBUF2 FRAMEWORK
+M:	Tomasz Figa <tfiga@chromium.org>
 M:	Pawel Osciak <pawel@osciak.com>
 M:	Marek Szyprowski <m.szyprowski@samsung.com>
 M:	Kyungmin Park <kyungmin.park@samsung.com>
-R:	Tomasz Figa <tfiga@chromium.org>
 L:	linux-media@vger.kernel.org
 S:	Maintained
 F:	drivers/media/common/videobuf2/*