[POWERPC] Set lower flag bits in regs->trap to indicate debug level exception

We use the low bits of regs->trap as flag bits.  We already indicate
critical and machine check level exceptions via this mechanism.  Extend it
to indicate debug level exceptions.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/ptrace.h b/include/asm-powerpc/ptrace.h
index 39023dd..38d87e5 100644
--- a/include/asm-powerpc/ptrace.h
+++ b/include/asm-powerpc/ptrace.h
@@ -119,6 +119,7 @@
 #ifndef __powerpc64__
 #define IS_CRITICAL_EXC(regs)	(((regs)->trap & 2) != 0)
 #define IS_MCHECK_EXC(regs)	(((regs)->trap & 4) != 0)
+#define IS_DEBUG_EXC(regs)	(((regs)->trap & 8) != 0)
 #endif /* ! __powerpc64__ */
 #define TRAP(regs)		((regs)->trap & ~0xF)
 #ifdef __powerpc64__