powerpc: Emulate icbi, mcrf and conditional-trap instructions

This extends the instruction emulation done by analyse_instr() and
emulate_step() to handle a few more instructions that are found in
the kernel.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 1a693b1..d3a42cc 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -66,6 +66,7 @@
 #define DCBF		0x100
 #define DCBTST		0x200
 #define DCBT		0x300
+#define ICBI		0x400
 
 /* Size field in type word */
 #define SIZE(n)		((n) << 8)