Add AVR architectures avr25, avr31, avr35, and avr51 to match GCC.

Add AVR architectures avr25, avr31, avr35, and avr51 to match GCC.
bfd/
	* archures.c (bfd_mach_avr25, bfd_mach_avr31, bfd_mach_avr35,
	bfd_mach_avr51): New.
	* bfd-in2.h: Regenerate.
	* cpu-avr.c (arch_info_struct): Add avr25, avr31, avr35, and avr51
	architectures. Change comments to match architecture comments in GCC.
	(compatible): Add test for new AVR architectures.
	* elf32-avr.c (bfd_elf_avr_final_write_processing): Recognize
	bfd_mach_avr25, bfd_mach_avr31, bfd_mach_avr35 and bfd_mach_avr51.
	(elf32_avr_object_p): Recognize E_AVR_MACH_AVR25, E_AVR_MACH_AVR31,
	E_AVR_MACH_AVR35 and E_AVR_MACH_AVR51.

gas/
	* config/tc-avr.c (mcu_types): Add avr25, avr31, avr35, and avr51
	architectures. Reorganize list to put mcu types in correct architectures
	and to order list same as in GCC. Use new ISA definitions in
	include/opcode/avr.h.
	* doc/c-avr.texi: Add avr25, avr31, avr35, and avr51 architecture
	descriptions. Reorganize descriptions to put mcu types in correct
	architectures and to order lists same as in GCC.

include/
	* elf/avr.h (E_AVR_MACH_AVR25, E_AVR_MACH_AVR31,
	E_AVR_MACH_AVR35, E_AVR_MACH_AVR51): Define.
	(EF_AVR_MACH): Redefine to 0x7F.
	* opcode/avr.h (AVR_ISA_TINY3, AVR_ISA_ALL, AVR_ISA_USB162): Remove.
	(AVR_ISA_AVR3): Redefine.
	(AVR_ISA_AVR1, AVR_ISA_AVR2, AVR_ISA_AVR31, AVR_ISA_AVR35,
	AVR_ISA_AVR3_ALL, AVR_ISA_AVR4, AVR_ISA_AVR5, AVR_ISA_AVR51,
	AVR_ISA_AVR6): Define.

ld/
	* Makefile.am (ALL_EMULATIONS): Add eavr25.o, eavr31.o, eavr35.o,
	and eavr51.o.
	Add rules for eavr25.c, eavr31.c, eavr35.c, eavr51.c.
	* Makefile.in: Regenerate.
	* configure.tgt (avr-*-*, targ_extra_emuls): Add avr25, avr31, avr35
	and avr51.
	* emulparams/avr25.sh: New file.
	* emulparams/avr31.sh: New file.
	* emulparams/avr35.sh: New file.
	* emulparams/avr51.sh: New file.