scsi: cxlflash: Refactor context reset to share reset logic

scsi: cxlflash: Refactor context reset to share reset logic

BugLink: http://bugs.launchpad.net/bugs/1702521
As staging for supporting hardware with different context reset
registers but a similar reset procedure, refactor the existing context
reset routine to move the reset logic to a common routine. This will
allow hardware with a different reset register to leverage existing
code.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 9c7d1ee5f13a7130f6d3df307ec010e9e003fa98)
Signed-off-by: Victor Aoqui <victora@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>