sh: Handle PCI controller resource conflicts.

sh: Handle PCI controller resource conflicts.

register_pci_controller() can fail, but presently is a void function.
Change this over to an int so that we can bail early before continuing on
with post-registration initialization (such as throwing the controller in
to 66MHz mode in the case of the SH7780 host controller).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>