testsuite: Fix up gcc.dg/pr102897.c testcase [PR102897]

testsuite: Fix up gcc.dg/pr102897.c testcase [PR102897]

The testcase FAILs on i686-linux due to:
FAIL: gcc.dg/pr102897.c (test for excess errors)
Excess errors:
.../gcc/gcc/testsuite/gcc.dg/pr102897.c:11:1: warning: MMX vector return without MMX enabled changes the ABI [-Wpsabi]
.../gcc/gcc/testsuite/gcc.dg/pr102897.c:10:10: warning: MMX vector argument without MMX enabled changes the ABI [-Wpsabi]
Fixed by adding -Wno-psabi.

2021-10-27  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/102897
	* gcc.dg/pr102897.c: Add -Wno-psabi to dg-options.