V4L2: H264 profile & level ctrls, FPS control and auto exp pri

Several control handling updates.
H264 profile and level controls.
Timeperframe/FPS reworked to add V4L2_CID_EXPOSURE_AUTO_PRIORITY to
select whether AE is allowed to override the framerate specified.

Signed-off-by: Dave Stevenson <dsteve@broadcom.com>
V4L2: Correct BGR24 to RGB24 in format table

Signed-off-by: Dave Stevenson <dsteve@broadcom.com>
V4L2: Add additional pixel formats. Correct colourspace

Adds the other flavours of YUYV, and NV12.
Corrects the overlay advertised colourspace.

Signed-off-by: Dave Stevenson <dsteve@broadcom.com>
V4L2: Drop logging msg from info to debug

Signed-off-by: Dave Stevenson <dsteve@broadcom.com>
V4L2: Initial pass at scene modes.

Only supports exposure mode and metering modes.

Signed-off-by: Dave Stevenson <dsteve@broadcom.com>
alsa: Make alsa work queue high priority. Fixes underrun issues when using negitive nice priority