Add support for G13 and G14 flag bits in RL78 ELF binaries.

Add support for G13 and G14 flag bits in RL78 ELF binaries.

inc	* rl78.h (E_FLAG_RL78_G10): Redefine.
	(E_FLAG_RL78_CPU_MASK, E_FLAG_RL78_ANY_CPU, E_FLAG_RL78_G13
	E_FLAG_RL78_G14): New flags.

bin	* readelf.c (get_machine_flags): Decode RL78's G13 and G14 flags.

gas	* config/tc-rl78.c (enum options): Add G13 and G14.
	(md_longopts): Add -mg13 and -mg14.
	(md_parse_option): Handle -mg13 and -mg14.
	(md_show_usage): List -mg13 and -mg14.
	* doc/c-rl78.texi: Add description of -mg13 and -mg14 options.

bfd	* elf32-rl78.c (rl78_cpu_name): New function.  Prints the name of
	the RL78 core based upon the flags.
	(rl78_elf_merge_private_bfd_data): Handle merging of G13 and G14
	flags.
	(rl78_elf_print_private_bfd_data): Use rl78_cpu_name.
	(elf32_rl78_machine): Always return bfd_mach_rl78.