V4L/DVB (11451): gspca - m5602-s5k83a: Add rotation, ctrl cache. Rename some ctrls.

s5k83a sensor mounted on many acer laptops have a swiwel allowing it to be rotated. When the camera is in its rotated state, the image needs to be flipped. The only way to check for if the camera has been flipped is to continously poll a register in the m5602. This patch creates a kernel thread which does this. This patch renames some v4l2 ctrls and finally implements a cache in order to prevent unnecessary sensor reads.

Signed-off-by: Luk?? Karas <lukas.karas@centrum.cz>
Signed-off-by: Erik Andr?n <erik.andren@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>