mfd: arizona: Correctly report when AIF2/AIF1 is underclocked

In the interrupt handler for an underclocked event, whilst checking for
the source of the interrupt, AIF3 was checked twice and AIF1 was not
checked. This change correctly checks the AIF1 underclocked bit and
reports the correct error messages for all cases.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>