rs6000/test: Fix selector in fold-vec-mule-misc.c

Run tests should use vmx_hw, not just powerpc_altivec_ok.

gcc/testsuite/
	PR target/94176
	* gcc.target/powerpc/fold-vec-mule-misc.c: Use vmx_hw selector.

gcc/testsuite/ChangeLog

+2020-03-14  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR target/94176
+	* gcc.target/powerpc/fold-vec-mule-misc.c: Use vmx_hw selector.
+
 2020-03-13  David Malcolm  <dmalcolm@redhat.com>
 
 	PR analyzer/94099

gcc/testsuite/gcc.target/powerpc/fold-vec-mule-misc.c

 /* PR target/79941 */
 
 /* { dg-do run } */
-/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-require-effective-target vmx_hw } */
 /* { dg-options "-maltivec -O2 -save-temps" } */
 
 #include <altivec.h>