scsi: cxlflash: Introduce OCXL backend

Add initial infrastructure to support a new cxlflash transport, OCXL.

Claim a dependency on OCXL and add a new file, ocxl_hw.c, which will host the
backend routines that are specific to OCXL.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/backend.h

@@ -13,6 +13,7 @@
  */
 
 extern const struct cxlflash_backend_ops cxlflash_cxl_ops;
+extern const struct cxlflash_backend_ops cxlflash_ocxl_ops;
 
 struct cxlflash_backend_ops {
 	struct module *module;