USB: dummy-hcd: fix power budget for SuperSpeed mode

commit 2636d49b

 upstream.

The power budget for SuperSpeed mode should be 900 mA
according to USB specification, so set the power budget
to 900mA for dummy_start_ss which is only used for
SuperSpeed mode.

If the max power consumption of SuperSpeed device is
larger than 500 mA, insufficient available bus power
error happens in usb_choose_configuration function
when the device connects to dummy hcd.

Signed-off-by: Jacky Cao <Jacky.Cao@sony.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/16EA1F625E922C43B00B9D82250220500871CDE5@APYOKXMS108.ap.sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>