usb: dwc3-msm: Reduce bus bandwidth vote based on device type

Driver currently votes for nominal bus bandwidth to enable/support
enhanced super speed devices. Vote can be reduced when high speed
devices (such as headset) are connected to allow additional
power savings.

Change-Id: I19277f223051d322b7bdf74c629627d39ac2b801
Signed-off-by: Vamsi Krishna Samavedam <vskrishn@codeaurora.org>