The main feature of the sparc-specific implementation of
pci_mmap_resource_range() is that it allows mapping the entire PCI I/O
space for a PCI host bridge using the /proc/bus/pci interface on a bridge
device.

The generic implementation cannot do this, but it also appears that this
got broken for sparc by commit 9eff02e2 ("PCI: check mmap range of
/proc/bus/pci files too"), which enforces that each address is part of a
BAR for kernels after 2.6.28.

Remove it all, assuming that the corresponding user space code has already
been changed to access /dev/ioport instead a long time ago.  Add
pci_iobar_pfn() to make it possible to map I/O resources. This is adapted
from the powerpc version.

Link: https://lore.kernel.org/lkml/1519887203.622.3.camel@infradead.org/t/
Link: https://lore.kernel.org/r/20220715153617.3393420-2-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>