fsi: core: Add trace events for scan and unregister

Add more trace events for the scanning and unregistration
functions for debug purposes.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230612195657.245125-9-eajames@linux.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>