[aarch64] move constants to rodata

[aarch64] move constants to rodata

The 3.6.0 has new assembly which again has constants in .text. This
breaks on platforms enforcing execute-only memory.

See, e.g., #24137 and PRs linked therein, among others.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
(Merged from https://github.com/openssl/openssl/pull/28726)