[media] introduce gspca-stk1135: Syntek STK1135 driver

Hello,
this is a new gspca driver for Syntek STK1135 webcams. The code is completely
new, but register values are based on Syntekdriver (stk11xx) by Nicolas VIVIEN
(http://syntekdriver.sourceforge.net

).
Only one webcam type is supported now - vendor 0x174f, device 0x6a31.
It's Asus F5RL laptop flippable webcam with MT9M112.
The camera works better than in Windows - initializes much faster and
provides more resolutions (the sensor can do almost any resolution - just
add it to the stk1135_modes[] - could this feature be somehow used by
applications to avoid SW scaling?).
Autoflip works too - when the camera is flipped around, the image is flipped
automatically.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>