MIPS: Netlogic: Fix PCIX irq on XLR chips

The correct irq is PIC_PCIX_IRQ

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3750/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>