ARM: dts: msm: Give Khaje its own MPM pins mapping configuration

Currently both Khaje and bengal 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: I558c545c76006f11b32bac41a45b8d4fe328a631