lbmk: remove "./buildpath mode all"

for example: ./build boot all

the "all" function is a relic from a much older lbmk
design, where for example we might have done:

./build clean all
./download all

this is no longer used, nor is this currently relevant
for the types of scripts present in lbmk.

we can always re-add this function later if needed,
but for now? remove unwanted code.

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

lbmk

@@ -96,13 +96,6 @@ execute_command()
 	case "${option}" in
 	list)
 		./build command options "${buildpath}/${mode}" ;;
-	all)
-		for option in $(./build command options "${buildpath}/${mode}")
-		do
-			"${buildpath}/${mode}/${option}" $@ || \
-			    fail "script fail: ${buildpath}/${mode}/${option} $@"
-		done
-		;;
 	*)
 		if [ ! -d "${buildpath}/${mode}" ]; then
 			usage $0