ARM: dts: msm: Specify max load currents for USB QMP PHY on sm8150

Add properties defining max load current for the vdd supply of
both QMP USB/DP PHY and the QMP USB Uni PHY on sm8150. Setting
the right load current allows the driver to correctly request the
correct regulator operation (HPM) when in use. 47mA is the value
specified in the power grid as the peak current for the UNI PHY.
Use this value also for USB-DP since we need only consider USB-only
use cases; DP will separately set its load which gets aggregated
with USB's in the concurrent use case.

Change-Id: Ifcdf3c9e8b83b24507a1ae7c697716e5bb3e5689
Signed-off-by: Jack Pham <jackp@codeaurora.org>