Tidy up functions.

2013-03-04  Jeremy Bennett <jeremy.bennett@embecosm.com>

	* arc-elf-tdep.c (arc_elf_cannot_fetch_register)
	(arc_elf_cannot_store_register): Remove osabi.
	* arc-linux-tdep.c (arc_linux_cannot_fetch_register)
	(arc_linux_cannot_store_register): Remove osabi.