AVX512FP16: Fix wrong code for _mm_mask_f[c]madd.*sch [PR 104978]

AVX512FP16: Fix wrong code for _mm_mask_f[c]madd.*sch [PR 104978]

For complex scalar intrinsic like _mm_mask_fcmadd_sch, the
mask should be and by 1 to ensure the mask is bind to lowest byte.
Use masked vmovss to perform same operation which omits higher bits
of mask.

gcc/ChangeLog:

	PR target/104978
	* config/i386/sse.md
	(avx512fp16_fmaddcsh_v8hf_mask1<round_expand_name):
	Use avx512f_movsf_mask instead of vmovaps or vblend, and
	force_reg before lowpart_subreg.
	(avx512fp16_fcmaddcsh_v8hf_mask1<round_expand_name): Likewise.

gcc/testsuite/ChangeLog:

	PR target/104978
	* gcc.target/i386/avx512fp16-vfcmaddcsh-1a.c: Adjust asm scan.
	* gcc.target/i386/avx512fp16-vfmaddcsh-1a.c: Ditto.
	* gcc.target/i386/avx512fp16-vfcmaddcsh-1c.c: Removed.
	* gcc.target/i386/avx512fp16-vfmaddcsh-1c.c: Ditto.
	* gcc.target/i386/pr104978.c: New test.