Makefiles: Add appropriate Makefiles to allow compilation on LE

Adds Makeiles and supporting files to enable compilition on LE
platforms. Required to enable RmNet Data feature on LE targets.

Change-Id: I2b9232eae0ad26d158bec077a2459261ea3cfecf
diff --git a/rmnetctl/cli/rmnetcli.c b/rmnetctl/cli/rmnetcli.c
index 2c4d099..7fe8a60 100644
--- a/rmnetctl/cli/rmnetcli.c
+++ b/rmnetctl/cli/rmnetcli.c
@@ -87,7 +87,7 @@
 * @param void
 * @return void
 */
-static void rmnet_api_usage()
+static void rmnet_api_usage(void)
 {
 	printf("RmNet API Usage:\n\n");
 	printf("rmnetcli help                            Displays this help\n");