V4L: omap camera builds again

V4L: omap camera builds again

Fix some bitrot, including basic build/load functionality:

  - ov9640 code had syntax errors (!) and referenced missing fields
  - camera core included all kinds of crap, but not the v4l2 stuff
  - both omap16xx and 17xx used the wrong base clock
  - 16xx oopsed because its base clock did not exist
  - misuse of machine_is_omap_h3() in place of cpu_is_omap1710()
  - several exported symbols were goofed up
  - used bad call to reserve mem region
  - didn't destroy platform device correctly
  - ov9640 needed MODULE_LICENSE("GPL")

It's probably best to think of this as just making the camera code
build again, load/unload as modules, stop oopsing on 16xx, and be
a smidgeon cleaner ... since my (early/prototype) Mistral board won't
actually get to UBoot when a camera is connected.  :(

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>