[media] SoC Camera: add driver for OMAP1 camera interface

This is a V4L2 driver for TI OMAP1 SoC camera interface.

Both videobuf-dma versions are supported, contig and sg, selectable with a
module option. The former uses less processing power, but often fails to
allocate contignuous buffer memory. The latter is free of this problem, but
generates tens of DMA interrupts per frame. If contig memory allocation ever
fails, the driver falls back to sg automatically on next open, but still can
be switched back to contig manually. Both paths work stable for me, even
under heavy load, on my OMAP1510 based Amstrad Delta videophone, that is the
oldest, least powerfull OMAP1 implementation.

The interface generally works in pass-through mode. Since input data byte
endianess can be swapped, it provides up to two v4l2 pixel formats per each of
several soc_mbus formats that have their swapped endian counterparts.

Boards using this driver can provide it with the following platform data:
- if and what freqency clock is...