media: MAINTAINERS: fix linux-media mailing list for meson drivers

Both MESON AO CEC and MESON VIDEO DECODER point to the wrong linux-media
mailing list. Update it to linux-media@vger.kernel.org.

Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>