lib: Correct printk %pF to work on all architectures

It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24f7bd0020f29ffe287dfdb9ead33ca0b2.  However,
the current way its coded doesn't work on parisc64.  For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors

Make dereference_function_descriptor() more accommodating by allowing
architecture overrides.  I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-parisc/sections.h b/include/asm-parisc/sections.h
index fdd43ec..9d13c35 100644
--- a/include/asm-parisc/sections.h
+++ b/include/asm-parisc/sections.h
@@ -4,4 +4,9 @@
 /* nothing to see, move along */
 #include <asm-generic/sections.h>
 
+#ifdef CONFIG_64BIT
+#undef dereference_function_descriptor
+void *dereference_function_descriptor(void *);
+#endif
+
 #endif