V4L/DVB (8752): s2255drv: firmware improvement patch

Fix for reloading firmware when removing and reloading driver
Handshaking for firmware loading and changing modes.
Removes the restriction of one user per channel at a time.
JPEG capture mode added.

Signed-off-by: Dean Anderson <dean@sensoray.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>