i386: psrlq is not used for PERM<a,{0},1,2,3,4> [PR113871]

Also handle V2BF mode.

	PR target/113871

gcc/ChangeLog:

	* config/i386/mmx.md (V248FI): Add V2BF mode.
	(V24FI_32): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr113871-5a.c: New test.
	* gcc.target/i386/pr113871-5b.c: New test.