i386/testsuite: Do not append AVX10.2 option for check_effective_target

i386/testsuite: Do not append AVX10.2 option for check_effective_target

When -avx10.2 meet -march with AVX512 enabled, it will report warning
for vector size conflict. The warning will prevent the test to run on
GCC with arch native build on those platforms when
check_effective_target.

Remove AVX10.2 options since we are using inline asm ad it actually do
not need options. It will eliminate the warning.

gcc/testsuite/ChangeLog:

	* lib/target-supports.exp (check_effective_target_avx10_2):
	Remove AVX10.2 option.
	(check_effective_target_avx10_2_512): Ditto.