[PATCH] Corgi touchscreen: Fix a pmu bug

Corgi Touchscreen bugfix.  If the PMU isn't running, the register needs to
be set to a sane value rather than reusing some random value.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>