Revert "usb: gadget: Draw 900mA current when enumerating in super speed mode"

This reverts commit b6cadaa8.
The same funcion was implemented by upstream android-4.9.216(4ad9bb85)
"usb: gadget: composite: Support more than 500mA MaxPower".

Change-Id: If81b633a492f565a6d53372a4e097c40b2c35835
Signed-off-by: jianzhou <jianzhou@codeaurora.org>