trees: move dependency building to new function

configure_project is a bit big. move the dependencies
build logic to a new function.

it may be desirable in future to make the way that
function works the way all build commands are done.

for example:

./update trees -b coreboot x230_12mb

would become:

./update trees -b coreboot/x230_12mb

this would enable to mix and match multi/single tree
projects. for now, leave things as they are.

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

script/trees

@@ -139,19 +139,22 @@ configure_project()
 	[ "$XBMK_RELEASE" = "y" ] && [ "$release" = "n" ] && return 1
 	[ -z "$btype" ] || [ "${mode%config}" = "$mode" ] || return 1
 
-	if [ -z "$mode" ]; then
+	[ -z "$mode" ] && build_dependencies
+
+	[ "$mode" = "fetch" ] || x_ ./update trees -f "$project" $target
+	[ "$mode" = "fetch" ] || return 0
+	[ -f "CHANGELOG" ] && return 1; fetch_${cmd#build_}; return 1
+}
+
+build_dependencies()
+{
 	for bd in $build_depend; do
 		bd_p="${bd%%/*}"; bd_t="${bd##*/}"
 		[ -z "$bd_p" ] && $dry $err "$project/$tree: !bd '$bd'"
 		[ "${bd##*/}" = "$bd" ] && bd_t=""
 		[ -z "$bd_p" ] || $dry ./update trees -b $bd_p $bd_t \
-			    || $err "!mk $project/$tree $bd_p/$bd_t"
-		done
-	fi
-
-	[ "$mode" = "fetch" ] || x_ ./update trees -f "$project" $target
-	[ "$mode" = "fetch" ] || return 0
-	[ -f "CHANGELOG" ] && return 1; fetch_${cmd#build_}; return 1
+		    || $err "!mk $project/$tree $bd_p/$bd_t"; continue
+	done; return 0
 }
 
 check_cross_compiler()