drivers: soc: apr: add wake_up for a waitqueue

APR client waits in a waitqueue for glink to queue intents.
On receiving notification about availability of intent, wake_up
should be called on the waitqueue to wake up any waiting APR
client.

CRs-Fixed: 1096481
Change-Id: I5a2b902fa831709092be1a9a3073b8d784adba81
Signed-off-by: Vikram Panduranga <vpandura@codeaurora.org>