staging: mt7621-pci: Hack 2 more PCI interrupts for gnubee1

The mt7621-pci support 3 pci devices and has 3 interrupts.
Each of these need to be enabled by the same sort of hack to
map hwirq number to virq number.
This is a hack which will go as soon as I understand how this is
supposed to work.

Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>