pci: pci-msm-msi: Re-name irq chip name for the driver

Rename msm_pci_msi to gic_msm_pci_msi. This allows irq
load balancer to take care of msi load balancing across
different core. Currently all msi interrupts are pinned
to core0.

Change-Id: I76877b61d84598a7794a4f70d0877b1203cbcc0a
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>