qseecom: fix a race condition when TA is blocked

When the thread processing blocked TA wakes up when listener
becames available, the listener may be unavailable again before
this thread grabs the global mutex, so make change to add a
while loop to check if listener available after wake up and hold
mutex.

Change-Id: Ib386faca7a44325142da1dc54e19a99f3173ec86
Signed-off-by: Zhen Kong <zkong@codeaurora.org>