[SCSI] bfa: use standards defined timeout for ELS/CT

Use standards defined 2 * RA_TOV as a timeout for ELS Request retries.
And standards defined 3 * RA_TOV as a timeout for FC-CT Request retries.
Also, added a check to send RPSC2 to a Brocade Fabric only.

Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>