The clearing was moved to the unmask hook because it is known to run
after the interrupt handler has actually run.  Before this patch, if
interrupts are threaded, the clearing/unmasking of level triggered
interrupts would be done before the threaded handler actually ran.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>