PPC: e500: Fix GPIO controller interrupt number

The GPIO controller lives at IRQ 47, not 43 on real hardware. This is a problem
because IRQ 43 is occupied by the I2C controller which we want to implement
next, so we'd have a conflict on that IRQ number.

Move the GPIO controller to IRQ 47 where it belongs.

Signed-off-by: Amit Singh Tomar <amit.tomar@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>