testsuite, rs6000: Replace powerpc_vsx_ok with powerpc_vsx

testsuite, rs6000: Replace powerpc_vsx_ok with powerpc_vsx

Following up the previous r15-886, this patch to clean up
the remaining powerpc_vsx_ok which actually should use
powerpc_vsx instead.

	PR testsuite/114842

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/error-1.c: Replace powerpc_vsx_ok check with
	powerpc_vsx.
	* gcc.target/powerpc/warn-2.c: Likewise.
	* gcc.target/powerpc/fold-vec-logical-ors-longlong.c: Likewise.
	* gcc.target/powerpc/ppc-fortran/pr80108-1.f90: Replace powerpc_vsx_ok
	check with powerpc_vsx and remove useless -mfloat128.
	* gcc.target/powerpc/pragma_power8.c: Replace powerpc_vsx_ok check with
	powerpc_vsx.