x86: apic.c declare pic_mode before they get used

Impact: cleanup, avoid sparse warning

In asm/mpspec.h moved out pic_mode from CONFIG_X86_32 as it is common
for both 32 and 64 bit.

Fixes this sparse warning for x86_64:

  arch/x86/kernel/apic.c:128:5: warning: symbol 'pic_mode' was not declared. Should it be static?
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/mpspec.h

@@ -6,13 +6,13 @@
 #include <asm/mpspec_def.h>
 
 extern int apic_version[MAX_APICS];
+extern int pic_mode;
 
 #ifdef CONFIG_X86_32
 #include <mach_mpspec.h>
 
 extern unsigned int def_to_bigsmp;
 extern u8 apicid_2_node[];
-extern int pic_mode;
 
 #ifdef CONFIG_X86_NUMAQ
 extern int mp_bus_id_to_node[MAX_MP_BUSSES];