Fix for missing MG24/MGM24 boards in silabs lighting-app EFR32 README

[lboue]

Fix for missing MG24/MGM24 boards in silabs lighting-app EFR32 README:

• BRD2703A / MG24 Explorer Kit
• BRD2704A / Sparkfun Thing Plus MGM240P board

[github-actions]

PR #26358: Size comparison from 7b60592 to f377e58

Increases (1 build for cc32xx)

platform	target	config	section	7b60592	f377e58	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL	.debug_info	19522329	19522330	1	0.0

Full report (1 build for cc32xx)

platform	target	config	section	7b60592	f377e58	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	604730	604730	0	0.0
			(read/write)	204156	204156	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197568	197568	0	0.0
			.comment	206	206	0	0.0
			.data	1468	1468	0	0.0
			.debug_abbrev	957005	957005	0	0.0
			.debug_aranges	101104	101104	0	0.0
			.debug_frame	341416	341416	0	0.0
			.debug_info	19522329	19522330	1	0.0
			.debug_line	2666090	2666090	0	0.0
			.debug_line_str	513	513	0	0.0
			.debug_loc	33340	33340	0	0.0
			.debug_loclists	1488725	1488725	0	0.0
			.debug_ranges	4984	4984	0	0.0
			.debug_rnglists	94279	94279	0	0.0
			.debug_str	3100491	3100491	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	104298	104298	0	0.0
			.shstrtab	265	265	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	482872	482872	0	0.0
			.symtab	287120	287120	0	0.0
			.text	498308	498308	0	0.0

[andy31415]

@lboue spellchecker claims Sparkfun is not a word. Please fix.

[lboue]

@lboue spellchecker claims Sparkfun is not a word. Please fix.
I just corrected this error.