power: qos: Use effective affinity mask

PM_QOS_REQ_AFFINE_IRQ request is supposed to apply the QoS vote
for the CPU(s) on which the attached interrupt arrives. Currently
the QoS vote is applied to all the CPUs present in the IRQ
affinity mask i.e desc->irq_data.common->affinity. However some
chips configure only a single CPU from this affinity mask to
receive the IRQ.  This information is present in effective
affinity mask of an IRQ. Start using it so that a QoS vote is
not applied to other CPUs on which the IRQ never comes but
present in the affinity mask.

Change-Id: If26aa23bebe4a7d07ffedb5ff833ccdb4f4fb6ea
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>