elf bfd.h tidy

elf bfd.h tidy

bfd/
	* bfd-in.h (enum notice_asneeded_action): Move to bfdlink.h.
	Move most other elf declarations..
	* elf-bfd.h: ..to here.
	* bfd-in2.h: Regenerate.
include/
	* bfdlink.h (enum notice_asneeded_action): Define.
ld/
	* deffilep.y: Include bfdlink.h.
	* ldelf.c: Likewise.
	* ldelfgen.c: Likewise.
	* ldver.c: Likewise.
	* mri.c: Likewise.
	* emultempl/irix.em: Don't include ld.h, ldmain.h, libiberty.h.
	Comment.