rom.sh: new file, to replace script/roms

stub it from the trees script. the way it works now,
there is less code in the build system.

./build roms

this is no longer a thing

./build roms serprog

this is also no longer a thing. instead, do:

./update trees -b coreboot targetnamehere

./update trees -b pico-serprog

./update trees -b stm32-vserprog

the old commands still works, which causes the new
commands to run

coreboot roms now appear in elf/, not bin/, as before,
but those images now contain payloads.

NOTE: to contradict the above: ./build roms is no
longer a thing, in that it's now deprecated, but
backward compatibility is present for now. it will
be removed in a future release.

./build roms list also still works! it will do:
./update trees -b coreboot list

also:
./update trees -b grub list
this is now possible too

if a target "list" is provided, for multi-tree sources,
the targets are shown.

there is another difference: seagrub roms are now seagrub_,
instead of seabios_withgrub.

seabios-only roms are no longer provided, where grub is also
enabled; only seagrub is used. the user can easily remove
the bootorder file, if they want seabios to not try grub first.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/lib.sh

@@ -10,7 +10,6 @@ _ua="Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0"
 kbnotice="Insert a .gkb file from config/data/grub/keymap/ as keymap.gkb \
 if you want a custom keymap in GRUB; use cbfstool from elf/cbfstool."
 
-cbelfdir="elf/.coreboot_nopayload_DO_NOT_FLASH"
 ifdtool="elf/ifdtool/default/ifdtool"
 cbfstool="elf/cbfstool/default/cbfstool"
 tmpgit="$PWD/tmp/gitclone"