s390: Fix unresolved iterators bhfgq and xdee

s390: Fix unresolved iterators bhfgq and xdee

Code attribute bhfgq is missing a mapping for TF.  This results in
unresolved iterators in assembler templates for *bswaptf.

With the TF mapping added the base mnemonics vlbr and vstbr are not
"used" anymore but only the extended mnemonics (vlbr<bhfgq> was
interpreted as vlbr; likewise for vstbr).  Therefore, remove the base
mnemonics from the scheduling description, otherwise, genattrtab would
error about unknown mnemonics.

Likewise, for movtf_vr only the extended mnemonics for vrepi are used,
now, which means the base mnemonic is "unused" and has to be removed
from the scheduling description.

Similarly, we end up with unresolved iterators in assembler templates
for mulfprx23 since code attribute xdee is missing a mapping for FPRX2.

Note, this is basically a cherry pick of commit r15-2060-ga4abda934aa426
with the addition that vrepi is removed from the scheduling description,
too.

gcc/ChangeLog:

	* config/s390/3931.md (vlbr, vstbr, vrepi): Remove.
	* config/s390/s390.md (xdee): Add FPRX2 mapping.
	* config/s390/vector.md (bhfgq): Add TF mapping.