ARM: dts: msm: Enable S1 SMMU for USB on Bengal

Enable Stage-1 SMMU for USB on Bengal and
pass the address range for IPA.
Also, use the base address as 0x50000000 instead of
the usual to support IPA to reduce memory usage on
32-bit architecture.

Change-Id: I2ff7898d6acd248d0e0d849e24539943e686515e