[SCSI] fnic: Fnic Statistics Collection

This feature gathers active and cumulative per fnic stats for io,
abort, terminate, reset, vlan discovery path and it also includes
various important stats for debugging issues. It also provided
debugfs and ioctl interface for user to retrieve these stats.
It also provides functionality to reset cumulative stats through
user interface.

Signed-off-by: Hiral Patel <hiralpat@cisco.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>