aarch64: Fix plugin header install

aarch64: Fix plugin header install

The r13-2943-g11a113d501ff64 made aarch64.h include
aarch64-option-extensions.def, but that file isn't installed
for building plugins.

On Wed, Dec 21, 2022 at 09:56:33AM +0000, Richard Sandiford wrote:
> Should this (and aarch64-fusion-pairs.def and aarch64-tuning-flags.def)
> be in TM_H instead?  The first two OPTIONS_H_EXTRA entries seem to be
> for aarch64-opt.h (included via aarch64.opt).
>
> I guess TM_H should also have aarch64-arches.def, since it's included
> for aarch64_feature.

gcc/Makefile.in has
TM_H      = $(GTM_H) insn-flags.h $(OPTIONS_H)
and
OPTIONS_H = options.h flag-types.h $(OPTIONS_H_EXTRA)
which means that adding something into TM_H when it is already in
OPTIONS_H_EXTRA is a unnecessary.
It is true that aarch64-fusion-pairs.def (included by aarch64-protos.h)
and aarch64-tuning-flags.def (ditto) and aarch64-option-extensions.def
(included by aarch64.h) aren't needed for options.h, so I think the
right patch would be following.

2022-12-22  Jakub Jelinek  <jakub@redhat.com>

	* config/aarch64/t-aarch64 (TM_H): Don't add aarch64-cores.def,
	add aarch64-fusion-pairs.def, aarch64-tuning-flags.def and
	aarch64-option-extensions.def.
	(OPTIONS_H_EXTRA): Don't add aarch64-fusion-pairs.def nor
	aarch64-tuning-flags.def.