media: doc: media: vimc: Update module parameter usage information

vimc driver is now a monolithic driver. Update the module parameter
usage information to reflect that.

[m.chehab+samsung@kernel.org: fix two warnings due to wrontly added spaces]

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>