Revert "msm: usb: add USB fast charge."

This reverts commit 3007745899b792ca361a6a361a8fb18ccc5d0096.
USB Fast Charge for Nexus 5

Increases input current limit to 900mA when charging via USB.
This patch does not force AC mode because this device is capable
of a charging at a much higher current limit than some USB ports
are able to deliver.