USB: ci13xxx: Don't fail ep_dequeue in suspend if USB not in LPM

Fail ep_dequeue only if USB is in LPM and don't check for USB
bus_suspend as some platforms or function drivers may not allow
USB LPM on bus_suspend.

Change-Id: I1217dc1fa2ac9d6d7b3ffe7498f143ef3fa5ec28
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>