Patch from Kevin Hilman

This time with IRQ versions of locks.

Rework also enables compatability with realtime-preemption patch.
With the current locking via interrupt disabling, under RT,
potentially sleeping functions can be called with interrupts
disabled.
Signed-off-by: NKevin Hilman <khilman@mvista.com>
Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>