testsuite: Fix pr113431.c FAIL on sparc* [PR113431]

As mentioned in the PR, the new testcase FAILs on sparc*-* due to
lack of support of misaligned store.

This patch restricts that to vect_hw_misalign targets.

2024-03-15  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113431
	* gcc.dg/vect/pr113431.c: Restrict scan-tree-dump-times to
	vect_hw_misalign targets.