ARM: dts: msm: Specify MIN bus vote for SM8150

DWC3 driver exposes a sysfs node to let user change
its bus vote to a lower or min value. This is needed to
run some test cases with USB cable connected and without
USB bus-vote impacting system power state which currently
stays at NOMINAL due to USB vote.

Change-Id: I019c956aabbe241640971a485703a919264faacb
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>