[media] gspca/sn9c20x: Fix support for mt9m001 (mi1300) sensor

Support for mt9m001 (mi1300) is broken:
	- Table is incomplete;
	- Only one resolution is currently supported by the driver;
	- Resolution is incomplete;
	- it complains about broken JPEG headers.

Use the same init found on em28xx driver, and properly report the
output format as 8-bits GRAY.

Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>