x86: drop redundant "prefix_data16" attributes

The attribute defaults to 1 for TI-mode insns of type sselog, sselog1,
sseiadd, sseimul, and sseishft.

In *<code>v8hi3 [smaxmin] and *<code>v16qi3 [umaxmin] also drop the
similarly stray "prefix_extra" at this occasion. These two max/min
flavors are encoded in 0f space.

gcc/

	* config/i386/mmx.md (*mmx_pinsrd): Drop "prefix_data16".
	(*mmx_pinsrb): Likewise.
	(*mmx_pextrb): Likewise.
	(*mmx_pextrb_zext): Likewise.
	(mmx_pshufbv8qi3): Likewise.
	(mmx_pshufbv4qi3): Likewise.
	(mmx_pswapdv2si2): Likewise.
	(*pinsrb): Likewise.
	(*pextrb): Likewise.
	(*pextrb_zext): Likewise.
	* config/i386/sse.md (*sse4_1_mulv2siv2di3<mask_name>): Likewise.
	(*sse2_eq<mode>3): Likewise.
	(*sse2_gt<mode>3): Likewise.
	(<sse2p4_1>_pinsr<ssemodesuffix>): Likewise.
	(*vec_extract<mode>): Likewise.
	(*vec_extract<PEXTR_MODE12:mode>_zext): Likewise.
	(*vec_extractv16qi_zext): Likewise.
	(ssse3_ph<plusminus_mnemonic>wv8hi3): Likewise.
	(ssse3_pmaddubsw128): Likewise.
	(*<ssse3_avx2>_pmulhrsw<mode>3<mask_name>): Likewise.
	(<ssse3_avx2>_pshufb<mode>3<mask_name>): Likewise.
	(<ssse3_avx2>_psign<mode>3): Likewise.
	(<ssse3_avx2>_palignr<mode>): Likewise.
	(*abs<mode>2): Likewise.
	(sse4_2_pcmpestr): Likewise.
	(sse4_2_pcmpestri): Likewise.
	(sse4_2_pcmpestrm): Likewise.
	(sse4_2_pcmpestr_cconly): Likewise.
	(sse4_2_pcmpistr): Likewise.
	(sse4_2_pcmpistri): Likewise.
	(sse4_2_pcmpistrm): Likewise.
	(sse4_2_pcmpistr_cconly): Likewise.
	(vgf2p8affineinvqb_<mode><mask_name>): Likewise.
	(vgf2p8affineqb_<mode><mask_name>): Likewise.
	(vgf2p8mulb_<mode><mask_name>): Likewise.
	(*<code>v8hi3 [smaxmin]): Drop "prefix_data16" and
	"prefix_extra".
	(*<code>v16qi3 [umaxmin]): Likewise.