* scripttempl/avr.sc (.bss): Set lma when relocating.
(.bss, .noinit): No need to set vma when relocating.
(.text, .bss, ,noinit): Set vma to zero when not relocating.
* emulparams/avr2.sh: New file.
* emulparams/avr3.sh: New file.
* emulparams/avr4.sh: New file.
* emulparams/avr5.sh: New file.
* scripttempl/avr.sc: New file.