broadcom-wl: add nvram stub to fix nas compile after the switch to unvram

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15439 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/broadcom-wl/src/nvram/nvram_stub.c

@@ -0,0 +1,16 @@
+#include <stdlib.h>
+
+int nvram_set(const char *name, const char *value)
+{
+	return -1;
+}
+
+char *nvram_get(const char *name)
+{
+	return NULL;
+}
+
+int nvram_unset(const char *name)
+{
+	return -1;
+}