Fix errors in the gas testsuite for the ARC target.

Fix errors in the gas testsuite for the ARC target.

bfd	* reloc.c (BFD_RELOC_ARC_32_PCREL): New entry.
	(ARC_TLS_DTPOFF): Arrange it in order.
	* elf32-arc.c (arc_elf_howto_ini): Update formula.
	(get_middle_endian_relocation): New function.
	(PDATA): Define.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Likewise.

elf	* arc-reloc.def (ARC_32_PCREL): New definition.

gas	* config/tc-arc.c (tokenize_arguments): Avoid creating unused
	symbols when parsing relocation types.
	(md_apply_fix): Handle TLS relocations. Fix BFD_RELOC_ARC_32_PCREL
	relocation.
	(arc_check_reloc): Emit BFD_RELOC_ARC_32_PCREL relocation.