module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y

powerpc applies relocations to the kcrctab.  They're absolute symbols,
but it's not completely unreasonable: other archs may too, but the
relocation is often 0.

http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html

Inspired-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/vmlinux.lds.S

@@ -38,6 +38,9 @@ jiffies = jiffies_64 + 4;
 #endif
 SECTIONS
 {
+	. = 0;
+	reloc_start = .;
+
 	. = KERNELBASE;
 
 /*