arm: irq: call irq affinity notifiers on cpu hotplug

Commit '813aa776 ("genirq: Use irq_set_affinity_locked 
to change irq affinity")' has introduced the change in generic
irq, which is needed by PM QoS to get irq affinity notifications,
but it is not addressing 32-bit cpu hotplug path.
 
So update 32-bit cpu hotplug path also to call irq_set_affinity_locked.

Change-Id: Ic5971b8a75a2faaf78d861d9e1e6989132beea79
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>