Remove af-event bits that are no longer used.

[bzbarsky-apple]

No description provided.

[github-actions]

PR #25191: Size comparison from 07b3c19 to 587960b

Decreases (3 builds for cc32xx, qpg)

platform	target	config	section	07b3c19	587960b	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL	(read/write)	203672	203664	-8	-0.0
			.bss	197072	197064	-8	-0.0
			.debug_abbrev	930533	930489	-44	-0.0
			.debug_info	20256440	20256265	-175	-0.0
			.debug_line	2656005	2655979	-26	-0.0
			.debug_loc	2796891	2796859	-32	-0.0
			.debug_str	3018892	3018700	-192	-0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1151348	1151332	-16	-0.0
			.bss	99812	99796	-16	-0.0
			.text	598444	598428	-16	-0.0
	lock-app	qpg6105+debug	.bss	96292	96284	-8	-0.0

Full report (3 builds for cc32xx, qpg)

platform	target	config	section	07b3c19	587960b	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	642529	642529	0	0.0
			(read/write)	203672	203664	-8	-0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197072	197064	-8	-0.0
			.comment	194	194	0	0.0
			.data	1480	1480	0	0.0
			.debug_abbrev	930533	930489	-44	-0.0
			.debug_aranges	87392	87392	0	0.0
			.debug_frame	300100	300100	0	0.0
			.debug_info	20256440	20256265	-175	-0.0
			.debug_line	2656005	2655979	-26	-0.0
			.debug_loc	2796891	2796859	-32	-0.0
			.debug_ranges	281688	281688	0	0.0
			.debug_str	3018892	3018700	-192	-0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	105817	105817	0	0.0
			.shstrtab	232	232	0	0.0
			.stab	204	204	0	0.0
			.stabstr	441	441	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	377598	377598	0	0.0
			.symtab	256144	256144	0	0.0
			.text	534588	534588	0	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1151348	1151332	-16	-0.0
			.bss	99812	99796	-16	-0.0
			.data	852	852	0	0.0
			.text	598444	598428	-16	-0.0
	lock-app	qpg6105+debug	(read/write)	1118348	1118348	0	0.0
			.bss	96292	96284	-8	-0.0
			.data	864	864	0	0.0
			.text	565448	565448	0	0.0