powerpc: Merge xmon

The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index bfb45a4..da84841 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -546,6 +546,7 @@
 #define __mtmsrd(v, l)	asm volatile("mtmsrd %0," __stringify(l) \
 				     : : "r" (v))
 #define mtmsrd(v)	__mtmsrd((v), 0)
+#define mtmsr(v)	mtmsrd(v)
 #else
 #define mtmsr(v)	asm volatile("mtmsr %0" : : "r" (v))
 #endif