ARM: dts: msm: Fix usage of uppercase with USB device nodes on msm8996

It is suggested to use lowercase for defining different base address
with devicetree. Hence fix usage of uppercase with USB device nodes
on msm8996.

Change-Id: I71b6d9414d52af8b7dc67da1aabd312807eab9c1
Signed-off-by: Mayank Rana <mrana@codeaurora.org>