i386: Correct mask width for bf8->fp16 intrin on 256/512 bit

i386: Correct mask width for bf8->fp16 intrin on 256/512 bit

For bf8 -> fp16 convert, when dst is 256 bit, the mask should be
16 bit since 16*16=256, not the 8 bit in the current intrin. In
512 bit intrin, the mask size is also halved. This patch will fix
both of them.

gcc/ChangeLog:

	* config/i386/avx10_2-512convertintrin.h
	(_mm512_mask_cvtbf8_ph): Correct mask width.
	(_mm512_maskz_cvtbf8_ph): Ditto.
	* config/i386/avx10_2convertintrin.h
	(_mm256_mask_cvtbf8_ph): Ditto.
	(_mm256_maskz_cvtbf8_ph): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/avx10_2-512-convert-1.c: Change function call.
	* gcc.target/i386/avx10_2-convert-1.c: Ditto.