soundwire: amd: fix for handling slave alerts after link is down

soundwire: amd: fix for handling slave alerts after link is down

Sometimes, its observed that during system level suspend callback
execution, after link is down, handling pending slave status workqueue
results in mipi register access failures as shown below.

soundwire sdw-master-0-0: trf on Slave 1 failed:-110 read addr 0 count 1
rt722-sdca sdw:0:0:025d:0722:01: SDW_DP0_INT recheck read failed:-110
rt722-sdca sdw:0:0:025d:0722:01: Slave 1 alert handling failed: -110
amd_sdw_manager amd_sdw_manager.0: SDW0 cmd response timeout occurred
amd_sdw_manager amd_sdw_manager.0: command timeout for Slave 1
soundwire sdw-master-0-0: trf on Slave 1 failed:-110 write addr 5c count 1
amd_sdw_manager amd_sdw_manager.0: SDW0 previous cmd status clear failed
amd_sdw_manager amd_sdw_manager.0: command timeout for Slave 1
soundwire sdw-master-0-0: trf on Slave 1 failed:-110 write addr 5d count 1
amd_sdw_manager amd_sdw_manager.0: SDW0 previous cmd status clear failed
amd_sdw_manager amd_sdw_manager.0: command timeout for Slave 1

Cancel the pending slave status workqueue prior to initiating clock stop
sequence during suspend callback execution for both the power modes.

Fixes: 9cf1efc5ed2d ("soundwire: amd: add pm_prepare callback and pm ops support")
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Link: https://lore.kernel.org/r/20250530054447.1645807-2-Vijendar.Mukunda@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>