Mark Power10 fusion option undocumented and remove sub-options.

gcc/
	* config/rs6000/rs6000.opt (mpower10-fusion): Mark Undocumented.
	(mpower10-fusion-ld-cmpi, mpower10-fusion-2logical,
	mpower10-fusion-logical-add, mpower10-fusion-add-logical,
	mpower10-fusion-2add, mpower10-fusion-2store): Remove.
	* config/rs6000/rs6000-cpus.def (ISA_3_1_MASKS_SERVER,
	OTHER_P9_VECTOR_MASKS): Remove Power10 fusion sub-options.
	* config/rs6000/rs6000.cc (rs6000_option_override_internal,
	power10_sched_reorder): Likewise.
	* config/rs6000/genfusion.pl (gen_ld_cmpi_p10, gen_logical_addsubf,
	gen_addadd): Likewise
	* config/rs6000/fusion.md: Regenerate.