ARM: dts: msm: Add macros for QMP USB register offsets on SDM855

Add macro definitions in a dt-bindings header file for all
the QMP USB DP and USB UNI PHY register offsets. This allows
for more straightforward entry in the DTS and aims to help
reduce typographical errors.

Change-Id: I61d2fab3e98c47fcb3d4a83a204584063d6db2f9
Signed-off-by: Jack Pham <jackp@codeaurora.org>