qseecom: set rcv_req_flag to 0 when listener is just registered

Only set rcv_req_flag to 0 when listener is just registered, as
if a client thread first sets rcv_req_flag to 1 when getting a new
listener request, and later on qseecomd calls qseecom_receive_req,
this flag will be overwritten to 0 and listener recv_req thread can
not be waken up. Also remove retry logic to wait for listener ready
and just return error response to TZ.

Change-Id: I35f4bcf3832d7cc987f7e0027a5cb25abd05d5b5
Signed-off-by: Zhen Kong <zkong@codeaurora.org>