[SPARC64]: Fix inline directive in pci_iommu.c

While building a test kernel for the new esp driver (against
git-current), I hit this bug. Trivial fix, put the inline declaration
in the right place. :)

Signed-off-by: Tom "spot" Callaway <tcallawa@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>