ARM: dts: msm: Add bus voting parameters to USB EHCI on 8994 and 8992

The USB2 host controller needs to update its MSM bus client
parameters in order to guarantee minimum bus frequencies needed
for correct operation.

Change-Id: Ib98f3a9227ac9d510fb4982a5cf9efb6e72ce7a6
Signed-off-by: Jack Pham <jackp@codeaurora.org>