qla2xxx: Correct iiDMA-update calling conventions.

* To set iiDMA speeds for ISP81XX, bits 5-0 are used whereas for
  other older ISPs bits 2-0 are used.
* Pass proper VP index

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