scsi: hisi_sas: tidy channel interrupt handler for v3 hw

scsi: hisi_sas: tidy channel interrupt handler for v3 hw

BugLink: https://bugs.launchpad.net/bugs/1794172
The ISR of channel interrupt of v3 hw is a little long and messy. This
patch tidies it by relocating CHL_INT1 and CHL_INT2 handling to new
function separately.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit d9d51e0cf462cf12956cbc95b1fd55d90c7c9ac5)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>