fix UP compilation

svn path=/head/; revision=197108

sys/i386/include/xen/xen-os.h

@@ -34,10 +34,10 @@ void force_evtchn_callback(void);
 #include <vm/pmap.h>
 #endif
 
+extern int gdtset;
 #ifdef SMP
 #include <sys/time.h> /* XXX for pcpu.h */
 #include <sys/pcpu.h> /* XXX for PCPU_GET */
-extern int gdtset;
 static inline int 
 smp_processor_id(void)  
 {

sys/i386/xen/locore.s

@@ -148,9 +148,7 @@ IdlePDPT:	.long	0		/* phys addr of kernel PDPT */
 	.globl	KPTphys
 #endif
 KPTphys:	.long	0		/* phys addr of kernel page tables */
-#ifdef SMP
 	.globl	gdtset
-#endif
 gdtset:		.long	0		/* GDT is valid */	
 
 	.globl	proc0kstack