iommu/amd: Move iommu_init_pci() to .init section

The function is only called from another __init function, so
it should be moved to .init too.
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_init.c

@@ -1709,7 +1709,7 @@ static const struct attribute_group *amd_iommu_groups[] = {
 	NULL,
 };
 
-static int iommu_init_pci(struct amd_iommu *iommu)
+static int __init iommu_init_pci(struct amd_iommu *iommu)
 {
 	int cap_ptr = iommu->cap_ptr;
 	u32 range, misc, low, high;