Makefile: fix runtime.bin target

src/Makefile

@@ -1,6 +1,6 @@
 VARIANT := simple
 
-all: ../build/firmware/armv7-none-eabihf/debug/szl ../build/firmware/armv7-none-eabihf/release/runtime
+all: ../build/firmware/armv7-none-eabihf/debug/szl ../build/firmware/armv7-none-eabihf/release/runtime ../build/firmware/armv7-none-eabihf/release/runtime.bin
 
 .PHONY: all
 
@@ -11,6 +11,8 @@ all: ../build/firmware/armv7-none-eabihf/debug/szl ../build/firmware/armv7-none-
 
 ../build/firmware/armv7-none-eabihf/release/runtime: ../build/pl.rs ../build/rustc-cfg $(shell find . -path ./szl -prune -o -print)
 	XBUILD_SYSROOT_PATH=`pwd`/../build/sysroot cargo xbuild --release -p runtime --target-dir ../build/firmware
+
+../build/firmware/armv7-none-eabihf/release/runtime.bin: ../build/firmware/armv7-none-eabihf/release/runtime
 	llvm-objcopy -O binary ../build/firmware/armv7-none-eabihf/release/runtime ../build/runtime.bin
 
 ../build/firmware/armv7-none-eabihf/debug/szl: .cargo/* armv7-none-eabihf.json Cargo.lock Cargo.toml szl/* szl/src/*