RISC-V: Remove autovec-vls.md file and clean up VLS move modes[NFC]

RISC-V: Remove autovec-vls.md file and clean up VLS move modes[NFC]

We have largely supportted VLS modes. Only move patterns of VLS modes are
different from VLS patterns. The rest of them are the same.

We always extend the current VLA patterns with VLSmodes:

VI --> V_VLSI
VF --> V_VLSF

It makes no sense to have a separate file holding a very few VLS patterns
that can not be extended from the current VLA patterns.

So remove autovec-vls.md

gcc/ChangeLog:

	* config/riscv/vector.md (mov<mode>): New pattern.
	(*mov<mode>_mem_to_mem): Ditto.
	(*mov<mode>): Ditto.
	(@mov<VLS_AVL_REG:mode><P:mode>_lra): Ditto.
	(*mov<VLS_AVL_REG:mode><P:mode>_lra): Ditto.
	(*mov<mode>_vls): Ditto.
	(movmisalign<mode>): Ditto.
	(@vec_duplicate<mode>): Ditto.
	* config/riscv/autovec-vls.md: Removed.