Runtime/Makefile: all goal should be default

Since clean rule is first target, just "make" means "make clean" as default goal.
This is a surprise. usually "make" means "make all".
So move all rule to the first target.

Signed-off-by: Isaku Yamahata <isaku.yamahata@gmail.com>

Runtime/Makefile

@@ -1,10 +1,10 @@
+.PHONY: all
+all:
+
 .PHONY: clean
 clean:
 	rm -f *.a *.o *.so *.so.* pal_gdb* pal-* pal_sec*
 
-.PHONY: all
-all:
-
 .PHONY: format
 format: