Staging: sxg: Add watchdog timer for managing Link states for SXG driver

Add a watchdog timer to take care of link change notifications.
Link changes would now be handled asynchronously as they involve large delays.

Signed-off-by: LinSysSoft Sahara Team <saharaproj@linsyssoft.com>
Signed-off-by: Mithlesh Thukral <mithlesh@linsyssoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>