testsuite: Adjust two bfp test cases with has_arch_ppc64 [PR108729]

testsuite: Adjust two bfp test cases with has_arch_ppc64 [PR108729]

Two test cases scalar-test-data-class-12.c and vec-test-data-class-9.c
fail on Power9 BE testing at -m32, they adopts a built-in function
scalar_insert_exp which requires powerpc64 support.  This patch
is to make them to check has_arch_ppc64 effective target requirement.

	PR testsuite/108729

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/bfp/scalar-test-data-class-12.c: Adjust with
	has_arch_ppc64 effective target.
	* gcc.target/powerpc/bfp/vec-test-data-class-9.c: Likewise.