IDL codegen type lookup: mark bitmaps to be bitmaps

[andy31415]

I belive a copy&paste resulted in bitmaps showing up as enums.

Fix this.

[github-actions]

PR #25827: Size comparison from 77e39a6 to 72a4a58

Full report (1 build for cc32xx)

platform	target	config	section	77e39a6	72a4a58	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	645697	645697	0	0.0
			(read/write)	203848	203848	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197248	197248	0	0.0
			.comment	194	194	0	0.0
			.data	1480	1480	0	0.0
			.debug_abbrev	930282	930282	0	0.0
			.debug_aranges	87376	87376	0	0.0
			.debug_frame	300292	300292	0	0.0
			.debug_info	20222885	20222885	0	0.0
			.debug_line	2661313	2661313	0	0.0
			.debug_loc	2805528	2805528	0	0.0
			.debug_ranges	283400	283400	0	0.0
			.debug_str	3021508	3021508	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	105953	105953	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	380469	380469	0	0.0
			.symtab	257408	257408	0	0.0
			.text	537624	537624	0	0.0