Make clang thread safety analysis configurable.

[andy31415]

Depending on CLANG version used, thread safety analysis may not be available. Found this when OSS-FUZZ tests were failing.

This CL adds a chip_enable_thread_safety_checks flag to turn these checks on/off and defaults them to on when the compiler is clang.

[github-actions]

PR #26422: Size comparison from a2d1596 to 2a89692

Increases (1 build for qpg)

platform	target	config	section	a2d1596	2a89692	change	% change
qpg	lighting-app	qpg6105+debug	(read/write)	1168216	1168224	8	0.0
			.text	615316	615324	8	0.0

Full report (3 builds for cc32xx, qpg)

platform	target	config	section	a2d1596	2a89692	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	604970	604970	0	0.0
			(read/write)	204164	204164	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197576	197576	0	0.0
			.comment	206	206	0	0.0
			.data	1468	1468	0	0.0
			.debug_abbrev	957619	957619	0	0.0
			.debug_aranges	101032	101032	0	0.0
			.debug_frame	341244	341244	0	0.0
			.debug_info	19608094	19608094	0	0.0
			.debug_line	2666175	2666175	0	0.0
			.debug_line_str	513	513	0	0.0
			.debug_loc	33340	33340	0	0.0
			.debug_loclists	1488806	1488806	0	0.0
			.debug_ranges	4984	4984	0	0.0
			.debug_rnglists	94237	94237	0	0.0
			.debug_str	3108637	3108637	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	104314	104314	0	0.0
			.shstrtab	265	265	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	483089	483089	0	0.0
			.symtab	287200	287200	0	0.0
			.text	498532	498532	0	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1168216	1168224	8	0.0
			.bss	99632	99632	0	0.0
			.data	856	856	0	0.0
			.text	615316	615324	8	0.0
	lock-app	qpg6105+debug	(read/write)	1138068	1138068	0	0.0
			.bss	94824	94824	0	0.0
			.data	856	856	0	0.0
			.text	585168	585168	0	0.0