AArch64: Cleanup fusion defines

AArch64: Cleanup fusion defines

Cleanup the fusion defines by introducing AARCH64_FUSE_BASE as a common base
level of fusion supported by almost all cores.  Add AARCH64_FUSE_MOVK as a
shortcut for all MOVK fusion.  In most cases there is no change.  It enables
AARCH64_FUSE_CMP_BRANCH for a few older cores since it has no measurable
effect if a core doesn't support it.  Also it may have been accidentally
left out on some cores that support all other types of branch fusion.

gcc/ChangeLog:

	* config/aarch64/aarch64-fusion-pairs.def (AARCH64_FUSE_BASE): New define.
	(AARCH64_FUSE_MOVK): Likewise.
	* config/aarch64/tuning_models/a64fx.h: Update.
	* config/aarch64/tuning_models/ampere1.h: Likewise.
	* config/aarch64/tuning_models/ampere1a.h: Likewise.
	* config/aarch64/tuning_models/ampere1b.h: Likewise.
	* config/aarch64/tuning_models/cortexa35.h: Likewise.
	* config/aarch64/tuning_models/cortexa53.h: Likewise.
	* config/aarch64/tuning_models/cortexa57.h: Likewise.
	* config/aarch64/tuning_models/cortexa72.h: Likewise.
	* config/aarch64/tuning_models/cortexa73.h: Likewise.
	* config/aarch64/tuning_models/cortexx925.h: Likewise.
	* config/aarch64/tuning_models/exynosm1.h: Likewise.
	* config/aarch64/tuning_models/fujitsu_monaka.h: Likewise.
	* config/aarch64/tuning_models/generic.h: Likewise.
	* config/aarch64/tuning_models/generic_armv8_a.h: Likewise.
	* config/aarch64/tuning_models/generic_armv9_a.h: Likewise.
	* config/aarch64/tuning_models/neoverse512tvb.h: Likewise.
	* config/aarch64/tuning_models/neoversen1.h: Likewise.
	* config/aarch64/tuning_models/neoversen2.h: Likewise.
	* config/aarch64/tuning_models/neoversen3.h: Likewise.
	* config/aarch64/tuning_models/neoversev1.h: Likewise.
	* config/aarch64/tuning_models/neoversev2.h: Likewise.
	* config/aarch64/tuning_models/neoversev3.h: Likewise.
	* config/aarch64/tuning_models/neoversev3ae.h: Likewise.
	* config/aarch64/tuning_models/qdf24xx.h: Likewise.
	* config/aarch64/tuning_models/saphira.h: Likewise.
	* config/aarch64/tuning_models/thunderx2t99.h: Likewise.
	* config/aarch64/tuning_models/thunderx3t110.h: Likewise.
	* config/aarch64/tuning_models/tsv110.h: Likewise.