scsi: cxlflash: Remove driver

Remove the cxlflash driver for IBM CAPI Flash devices.

The cxlflash driver has received minimal maintenance for some time, and
the CAPI Flash hardware that uses it is no longer commercially available.

Thanks to Uma Krishnan, Matthew Ochs and Manoj Kumar for their work on
this driver over the years.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20250203072801.365551-2-ajd@linux.ibm.com


Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>