[SCSI] qla2xxx: Retrieve board serial-number and description from VPD.

Recent ISPs have this information written at manufacturing time,
so use the information.  This also reduces future churn of the
qla_devtbl.h file contents, as the driver can now depend on the
information to be present in VPD.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>