usb: usb_bam: Prevent double access to finish suspend

This commit fixes a crash in disconnect cable, caused by
race condition of consumer release and suspend sequence.
Due to race condition the finish suspend function was entered
twice and was causing unclocked access.

Change-Id: I435a5c03b3fc63b5775ad94cece7097707b1c687
Signed-off-by: Lena Salman <esalman@codeaurora.org>
Signed-off-by: Amit Blay <ablay@codeaurora.org>