defconfig: msm: enable PCIe MSI for sa6155P

PCIe bus driver no longer supports QGIC. Enable PCIe MSI
controller for sa6155p so that QGIC MSI is supported.

Change-Id: I33b2558f326bff7b3386fc282a261d9a315eb9b6
Signed-off-by: Rama Krishna Phani A <rphani@codeaurora.org>