This patch adds function pointer to invoke disable interrupt for
xscale and ppc IOP based controllers. Removes old implementation that checks
for controller type in megasas_disable_intr.
Signed-off-by: NSumant Patro <Sumant.Patro@lsil.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>