[AArch64] Add ifunc support for Ares

Add Ares to the midr_el0 list and support ifunc dispatch.  Since Ares
supports 2 128-bit loads/stores, use Neon registers for memcpy by
selecting __memcpy_falkor by default (we should rename this to
__memcpy_simd or similar).

	* manual/tunables.texi (glibc.cpu.name): Add ares tunable.
	* sysdeps/aarch64/multiarch/memcpy.c (__libc_memcpy): Use
	__memcpy_falkor for ares.
	* sysdeps/unix/sysv/linux/aarch64/cpu-features.h (IS_ARES):
	Add new define.
	* sysdeps/unix/sysv/linux/aarch64/cpu-features.c (cpu_list):
	Add ares cpu.

(cherry picked from commit 02f440c1)