arm/dt: msm8226: Specify MIN BUS voting till USB cable is connected

MSM8226 requires voting for NOC bandwidth (and PNOC clocks) when
enabling/disabling USB clocks. Hence, add BUS bandwidth vote for
the same.

CRs-Fixed: 494654
Change-Id: I08d1766428121030ea0c282dbfddda05e1f752d3
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>