omap_uwire: SPI_CPHA mode bugfix

The omap_uwire controller driver handles SPI_CPHA incorrectly;
It should mean:

  CPHA=0 ... sample at leading edge of clock
  CPHA=1 ... sample at trailing edge of clock

This bug has been masked by inverse bugs in layered drivers;
and was uncovered by running some of them on non-OMAP hardware.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>