generic, x86: fix __per_cpu_load relocation

This patch fixes this linker error:

 WARNING: Absolute relocations present
 Offset     Info     Type     Sym.Value Sym.Name
 c0a4e07d 00e78001   R_386_32 c0ab0000  __per_cpu_load

Now, __per_cpu_load is a section-relative symbol:

 c0aa4000 D __per_cpu_load
 c0aa4000 A __per_cpu_load_abs

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>