tools/coreutils: install readlink

Parts of the build system use non-portable invocation of readlink

Signed-off-by: Felix Fietkau <nbd@nbd.name>

tools/coreutils/Makefile

@@ -15,14 +15,14 @@ PKG_HASH:=8891d349ee87b9ff7870f52b6d9312a9db672d2439d289bc57084771ca21656b
 
 HOST_BUILD_PARALLEL := 1
 
-BUILD_PROGRAMS = date
+BUILD_PROGRAMS = date readlink
 
 include $(INCLUDE_DIR)/host-build.mk
 
 BUILD_BINS = $(patsubst %,src/%,$(BUILD_PROGRAMS))
 
 HOST_CONFIGURE_ARGS += \
-	 --enable-install-program=date
+	 --enable-install-program=$(subst $(space),$(comma),$(strip $(BUILD_PROGRAMS)))
 
 HOST_MAKE_FLAGS += \
 	PROGRAMS="$(BUILD_BINS)" \