soc: qcom: glink: fix parameter validation

Input argument is failing the glink_open() call if the optional
notify_rx_intent_req argument is not provided.

Remove check since a dummy implementation is automatically provided
if necessary.

Change-Id: I1bed01433bd1c3f86f7907c368fb03358958f5a3
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>