powerpc: emulate_step() tests for load/store instructions

Add new selftest that test emulate_step for Normal, Floating Point,
Vector and Vector Scalar - load/store instructions. Test should run
at boot time if CONFIG_KPROBES_SANITY_TEST and CONFIG_PPC64 is set.

Sample log:

  emulate_step_test: ld             : PASS
  emulate_step_test: lwz            : PASS
  emulate_step_test: lwzx           : PASS
  emulate_step_test: std            : PASS
  emulate_step_test: ldarx / stdcx. : PASS
  emulate_step_test: lfsx           : PASS
  emulate_step_test: stfsx          : PASS
  emulate_step_test: lfdx           : PASS
  emulate_step_test: stfdx          : PASS
  emulate_step_test: lvx            : PASS
  emulate_step_test: stvx           : PASS
  emulate_step_test: lxvd2x         : PASS
  emulate_step_test: stxvd2x        : PASS

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
[mpe: Drop start/complete lines, make it all __init]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index d99bd44..e7d6d86 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -284,6 +284,13 @@
 #define PPC_INST_BRANCH_COND		0x40800000
 #define PPC_INST_LBZCIX			0x7c0006aa
 #define PPC_INST_STBCIX			0x7c0007aa
+#define PPC_INST_LWZX			0x7c00002e
+#define PPC_INST_LFSX			0x7c00042e
+#define PPC_INST_STFSX			0x7c00052e
+#define PPC_INST_LFDX			0x7c0004ae
+#define PPC_INST_STFDX			0x7c0005ae
+#define PPC_INST_LVX			0x7c0000ce
+#define PPC_INST_STVX			0x7c0001ce
 
 /* macros to insert fields into opcodes */
 #define ___PPC_RA(a)	(((a) & 0x1f) << 16)