Add AArch64 64-bit relocation values. These will be needed by rtld when
we import it along with utilities in elftoolchain.

Differential Revision:	https://reviews.freebsd.org/D1330
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275903 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f