qcom: mpm-of: fix bug in finding the pending interrupts

When APPS proc wakeup from RPM assisted PC states it reads
the vMPM status register to know the reason for wakeup and
retrigger the interrupts to handle it. Current code is not
caring about actual enabled interrupts in vMPM. Sometimes
this is causing APPS proc unnecessarily triggering the
interrupts which the not raised in the system. Fix this by
considering the enabled interrupts in vMPM before triggering
the interrupts.

CRs-fixed: 623293
Change-Id: Ia793e6d501cac3d85b51ed6e359703239a4b9945
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>