[GAS][AARCH64]Add BFD_RELOC_AARCH64_TLSGD_MOVW_G0_NC support.
bfd/
2015-10-02  Renlin Li <renlin.li@arm.com>
	* reloc.c (BFD_RELOC_AARCH64_TLSGD_MOVW_G0_NC): New entry.
	* elfnn-aarch64.c (elfNN_aarch64_howto_table): New entry for
	BFD_RELOC_AARCH64_TLSGD_MOVW_G0_NC.
	* libbfd.h: Regenerate.
	* bfd-in2.h: Likewise
gas/
2015-10-02  Renlin Li <renlin.li@arm.com>
	* config/tc-aarch64.c (reloc_table): New relocation modifier tlsgd_g0_nc.
	(process_movw_reloc_info): Support BFD_RELOC_AARCH64_TLSGD_MOVW_G1.
	(md_apply_fix): Likewise.
	(aarch64_force_relocation): Likewise.
gas/testsuite/
2015-10-02  Renlin Li <renlin.li@arm.com>
	* gas/aarch64/reloc-tlsgd_g0_nc.d: New.
	* gas/aarch64/reloc-tlsgd_g0_nc.s: New.