USB: f_fs: Disable USB LPM on bus_suspend with ADB

ADB function is mainly used for debugging, hence it is
not expected to allow USB LPM followed by system suspend
in device bus suspend. Driver also doesn't handle
usb_ep_dequeue failure in LPM when adbd is interrupted
by signal as buffer is left queued to the hardware after
usb_ep_dequeue failure and can cause memory corruption.

Change-Id: Ib89c80318dcdd0dbb35d122a2ab77fb61f83518e
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>