This patch adds RGB555 pixel format support to the vivi driver. Both
little endian and big endian versions are added. The driver follows
the RGB pixel format described in Table 2-2 of the V4L2 API spec,
_not_ the older BGR interpretation described in Table 2-1.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>