soc: qcom: spm: add support for AVS interrupt control

Add support for consumers to enable, disable, and clear the AVS
min and max interrupts.  These interrupts are triggered when
hardware attempts to raise or lower the AVS voltage outside of
the configured limits.

Change-Id: I84128265901687436405d689b5aa583677deb176
Signed-off-by: David Collins <collinsd@codeaurora.org>