Add MTE register set support for core files

	* elf-bfd.h (elfcore_write_aarch_mte): New prototype.
	* elf.c (elfcore_grok_aarch_mte, elfcore_write_aarch_mte): New
	functions.
	(elfcore_grok_note): Handle notes of type NT_ARM_TAGGED_ADDR_CTRL.
	(elfcore_write_register_note): Handle MTE notes.