Replace multiple AVR scripts with a single, customizable linker script.

Replace multiple AVR scripts with a single, customizable linker script.

	PR ld/21569
        * scripttempl/avrtiny.sc: Remove file.
	* Makefile.am (eavrtiny.c): Depend on avr.sc, no more on avrtiny.sc.
	* Makefile.in: Regenerate.
	* emulparams/avrtiny.sh (SCRIPT_NAME): Set var to "avr".
	(TEXT_ORIGIN): Remove var.
	(FUSE_NAME, FUSE_LENGTH, LOCK_LENGTH, SIGNATURE_LENGTH)
	(RODATA_PM_OFFSET): Set new vars.
	* emulparams/avr1.sh (FUSE_NAME, EEPROM_LENGTH, FUSE_LENGTH)
	(LOCK_LENGTH, SIGNATURE_LENGTH, USER_SIGNATURE_LENGTH): Set new vars.
	* emulparams/avr2.sh: Same.
	* emulparams/avr25.sh: Same.
	* emulparams/avr3.sh: Same.
	* emulparams/avr31.sh: Same.
	* emulparams/avr35.sh: Same.
	* emulparams/avr4.sh: Same.
	* emulparams/avr5.sh: Same.
	* emulparams/avr51.sh: Same.
	* emulparams/avr6.sh: Same.
	* emulparams/avrxmega1.sh: Same.
	* emulparams/avrxmega2.sh: Same.
	* emulparams/avrxmega3.sh: Same.
	* emulparams/avrxmega4.sh: Same.
	* emulparams/avrxmega5.sh: Same.
	* emulparams/avrxmega6.sh: Same.
	* emulparams/avrxmega7.sh: Same.
	* scripttempl/avr.sc (__EEPROM_REGION_LENGTH__): Only define
	if EEPROM_LENGTH is set.
	(MEMORY) [eeprom]: Same.
	(SECTIONS) [.eeprom]: Same for output section.
	(__USER_SIGNATURE_REGION_LENGTH__): Only define if
	USER_SIGNATURE_LENGTH is set.
	(MEMORY) [user_signatures]: Same.
	(SECTIONS) [.fuse]: Only define output section if FUSE_NAME = fuse.
	(SECTIONS) [.config]: Only define output section if FUSE_NAME = config.