qcacld-3.0: Fix -Wmissing-prototypes in lim_sme_req_utils

We want to enable the compiler's -Wmissing-prototypes switch, but
there is existing code that is generating warnings. Fix all warnings
in lim_sme_req_utils.

Change-Id: I7b0404a3ca41aa038b9e7db313eb1aadb6b92517
CRs-Fixed: 1075090

core/mac/src/pe/lim/lim_sme_req_utils.c

@@ -49,6 +49,7 @@
 #include "lim_assoc_utils.h"
 #include "lim_security_utils.h"
 #include "lim_ser_des_utils.h"
+#include "lim_sme_req_utils.h"
 
 /**
  * lim_is_rs_nie_valid_in_sme_req_message()