msm: Add header file for QPNP interrupt support

QPNP is a Qualcomm SPMI based implementation that specifies 256
devices per SPMI slave ID, with up to 8 interrupts per device.
This brings the theoretical max interrupt support to 32768 per
bus for this architecture.

This header file is added before the driver to satisfy circular
dependency with the PMIC Arbiter driver, which makes calls into
QPNP.

Change-Id: Ie563f55c0557771b8925c10762094cf191544a30
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>