srat's node_to_pxm() references pxm2node[] after init. so pxm2node[]
should not be __initdata.

Error: ./arch/x86_64/mm/srat.o .text refers to 0000000000000008 R_X86_64_32S      .init.data
Error: ./arch/x86_64/mm/srat.o .text refers to 0000000000000015 R_X86_64_32S      .init.data
Signed-off-by: Randy Dunlap <rddunlap@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>