selftests/powerpc: Move shared headers into new include dir

There are some functions, especially register related, which can
be shared across multiple selftests/powerpc test directories.

This patch creates a new include directory to store those shared
files, so that the file layout becomes more neat.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
[mpe: Reworked to move the headers only]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/tm/tm-signal.S

@@ -7,11 +7,11 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include "../basic_asm.h"
-#include "../gpr_asm.h"
-#include "../fpu_asm.h"
-#include "../vmx_asm.h"
-#include "../vsx_asm.h"
+#include "basic_asm.h"
+#include "gpr_asm.h"
+#include "fpu_asm.h"
+#include "vmx_asm.h"
+#include "vsx_asm.h"
 
 /*
  * Large caveat here being that the caller cannot expect the

tools/testing/selftests/powerpc/tm/tm.h

@@ -10,7 +10,7 @@
 #include <asm/cputable.h>
 #include <stdbool.h>
 
-#include "../utils.h"
+#include "utils.h"
 
 static inline bool have_htm(void)
 {