ipc: initialize glink link state

There is a chance that glink channel memory pointer is used
after free if WDSP_REG_PKT and WDSP_CMD_PKT are received at
the same time from different threads. Fix this issue by
initializing glink link state to GLINK_LINK_STATE_DOWN.
Also limit error logs to avoid watchdog timeout issues.

Change-Id: I07c4e6f12eb057405eb59f1c0d04b890fa964ce8
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>