added User Key domain to valid keys for the NVM3 Silabs implemented API

[HusseinElsherbini]

added the User key domain to valid keys for the NVM3 Silabs implemented API to facilitate development experience for end user.

[jmartinez-silabs]

thank you.

[github-actions]

PR #24974: Size comparison from 36735ed to 50cc59b

Increases (1 build for cc32xx)

platform	target	config	section	36735ed	50cc59b	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL	.debug_info	20194395	20194396	1	0.0

Full report (1 build for cc32xx)

platform	target	config	section	36735ed	50cc59b	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	640233	640233	0	0.0
			(read/write)	204084	204084	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197488	197488	0	0.0
			.comment	194	194	0	0.0
			.data	1476	1476	0	0.0
			.debug_abbrev	928439	928439	0	0.0
			.debug_aranges	87352	87352	0	0.0
			.debug_frame	299840	299840	0	0.0
			.debug_info	20194395	20194396	1	0.0
			.debug_line	2649797	2649797	0	0.0
			.debug_loc	2785922	2785922	0	0.0
			.debug_ranges	280720	280720	0	0.0
			.debug_str	3001474	3001474	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	105585	105585	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	375840	375840	0	0.0
			.symtab	255856	255856	0	0.0
			.text	532524	532524	0	0.0