MIPS: ath79: register PCI controller on the PB44 board

The PB44 reference board has two miniPCI slots. Register
the PCI controller to make those usable.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3502/


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