SUMMARY:
This is mostly some small cleanups and bug fixes. The biggest change is that
the OV7x20 contrast control is fixed. Previously, the contrast setting could
get corrupted after a while, causing the picture to be excessively dark.

PER-FILE CHANGES:
(+: New, -: Removed, *: Cleanup, @: Bugfix, =: Sync with kernel)

[Makefile]
@ Fixed detection of RedHat 9 errata kernels.

[Both USB drivers]
* Don't include /proc-related headers unless CONFIG_VIDEO_PROC_FS is defined.
= CodingStyle cleanups.

[ov511.c]
* Enable framedrop here instead of in the sensor code.
* Simplify error handling in ov51x_probe().

[ov6x20.c]
[ov76be.c]
[ov7x10.c]
* Move framedrop hack to ov511_core.c. This way, W9968CF won't suffer reduced
  frame rate due to OV511's flaws.

[ov7x20.c]
@ Fixed erratic OV7x20 contrast control. The value read wasn't matching the
  value written. Due to the nature of V4L1, this would corrupt the contrast
  setting every time another picture control was changed.

[ovcamchip_core.c]
+ Add ID for W9968CF driver.