arm: Move arm_simd_info array declaration into header

Move the arm_simd_type and arm_type_qualifiers enums, and
arm_simd_info struct from arm-builtins.c into arm-builtins.h header.

This is a first step towards internalising the type definitions for
MVE predicate, vector, and tuple types.  By moving arm_simd_types into
a header, we allow future patches to use these type trees externally
to arm-builtins.c, which is a crucial step towards developing an MVE
intrinsics framework similar to the current SVE implementation.

gcc/ChangeLog:

	* config/arm/arm-builtins.c (enum arm_type_qualifiers): Move to
	arm_builtins.h.
	(enum arm_simd_type): Move to arm-builtins.h.
	(struct arm_simd_type_info): Move to arm-builtins.h.
	* config/arm/arm-builtins.h (enum arm_simd_type): Move from
	arm-builtins.c.
	(enum arm_type_qualifiers): Move from arm-builtins.c.
	(struct arm_simd_type_info): Move from arm-builtins.c.