scsi: ufs: core: Introduce HBA performance monitor sysfs nodes

Add a new sysfs group which has nodes to monitor data/request transfer
performance. This sysfs group has nodes showing total sectors/requests
transferred, total busy time spent and max/min/avg/sum latencies. This
group can be enhanced later to show more UFS driver layer performance
statistics data during runtime.

Link: https://lore.kernel.org/r/1619058521-35307-2-git-send-email-cang@codeaurora.org
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Acked-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>