MIPS: Set io_map_base for several PCI bridges lacking it

MIPS: Set io_map_base for several PCI bridges lacking it

Several MIPS platforms don't set pci_controller::io_map_base for their
PCI bridges.  This results in a panic in pci_iomap().  (The panic is
conditional on CONFIG_PCI_DOMAINS, but that is now enabled for all PCI
MIPS systems.)

Signed-off-by: Ben Hutchings <[email protected]>
Cc: [email protected]
Cc: Martin Michlmayr <[email protected]>
Cc: Aurelien Jarno <[email protected]>
Cc: [email protected]
Patchwork: https://patchwork.linux-mips.org/patch/1377/
Signed-off-by: Ralf Baechle <[email protected]>