Disable X86_TUNE_AVX256_MOVE_BY_PIECES and STORE_BY_PIECES for znver1-3

Disable X86_TUNE_AVX256_MOVE_BY_PIECES and STORE_BY_PIECES for znver1-3

I have enabled SSE moves for znver1-3 since they are performance win on this
machine too (we avoid using loops or string operations which are more costy).
However as discussed in the PR log, this triggers bug in IRA and it was decided
it is better to not backport the fix.

gcc/ChangeLog:

2023-04-14  Jan Hubicka  <hubicka@ucw.cz>

	PR target/109137
	* config/i386/x86-tune.def (X86_TUNE_AVX256_MOVE_BY_PIECES):
	Remove znver1-3.
	(X86_TUNE_AVX256_STORE_BY_PIECES): Remove znver1-3.