irqchip: mpm: Add mpm mapping for Khaje

Currently both Bengal and Khaje use the same MPM pins mapping
configuration as they use the same compatible string. USB PHY
has a different GIC IRQ on Khaje, so different MPM configuration
is required.

Change-Id: I680bb0529145dfe2166f5b26d934da34e5c52f98
Signed-off-by: Raghavendra Kakarla <rkakarla@codeaurora.org>