[media] SOLO6x10: Fix video frame type (I/P/B)

Mask v4l2_buf.flags to indicate only I/P/B frames.

Signed-off-by: Krzysztof Ha?asa <khalasa@piap.pl>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>