[SCSI] lpfc 8.3.27: Changed worst case mailbox timeout

Changed the timeout value for flash-based SLI_CONFIG (0x9B)
mailbox command to 300 seconds for worst case flash delays.

Signed-off-by: Alex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>