soc: qcom: glink_loopback_server: Add request intent flag for tx

Loopback server is not using request intent flag while calling
glink_tx. This result in transaction failure without waiting
for intent.

GLINK_TX_REQ_INTENT flag is added, so that glink will wait for
remote side to queue intent.

CRs-Fixed: 2117763
Change-Id: Ia4aec8d7f0046b7af4fe853fcec86bdc18386619
Signed-off-by: Dhoat Harpal <hdhoat@codeaurora.org>