powerpc: Add PPC_NOP_INSTR, a hash define for the preferred nop instruction

A bunch of code has hard-coded the value for a "nop" instruction, it
would be nice to have a #define for it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/code-patching.h b/include/asm-powerpc/code-patching.h
index 40ad46b..ef3a5d1 100644
--- a/include/asm-powerpc/code-patching.h
+++ b/include/asm-powerpc/code-patching.h
@@ -12,6 +12,8 @@
 
 #include <asm/types.h>
 
+#define PPC_NOP_INSTR	0x60000000
+
 /* Flags for create_branch:
  * "b"   == create_branch(addr, target, 0);
  * "ba"  == create_branch(addr, target, BRANCH_ABSOLUTE);