powerpc/4xx: Fix build of PCI code on 405

Commit 112d1fe9
"powerpc/4xx: Add check_link to struct ppc4xx_pciex_hwops" inadvertently
broke 405 builds due to some functions being over protected by an
ifdef CONFIG_44x.

Move them back out.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>