PCI: Remove __weak tag from pci_remap_iospace()

pci_remap_iospace() is marked as a weak symbol even though no architecture
is currently overriding it; given that its implementation internals have
already code paths that are arch specific (ie PCI_IOBASE and
ioremap_page_range() attributes) there is no need to leave the weak symbol
in the kernel since the same functionality can be achieved by customizing
per-arch the corresponding functionality.

Remove the __weak symbol from pci_remap_iospace().

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>