[POWERPC] Make cpus_in_xmon static and remove extern mess from hvc_console.c

This is a little messier than I'd like because xmon.h only exists
on powerpc and we can't have a static inline and an extern declaration
visible at the same time.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/xmon.h b/include/asm-powerpc/xmon.h
index d83da3c..5eb8e59 100644
--- a/include/asm-powerpc/xmon.h
+++ b/include/asm-powerpc/xmon.h
@@ -25,5 +25,9 @@
 static inline void xmon_register_spus(struct list_head *list) { };
 #endif
 
+#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
+extern int cpus_are_in_xmon(void);
+#endif
+
 #endif /* __KERNEL __ */
 #endif /* __ASM_POWERPC_XMON_H */