qcacmn: Add support for AES ctr mode for kernel 3.18

Add changes to support AES CTR modes for FILS encryption and
decryption.

Change-Id: I418e85987bfa96efb7b9dc10e9b2125290299c89
CRs-Fixed: 2039626

qdf/inc/qdf_crypto.h

@@ -47,6 +47,9 @@ extern "C" {
 #define FIXED_PARAM_OFFSET_ASSOC_REQ 4
 #define FIXED_PARAM_OFFSET_ASSOC_RSP 6
 
+#define IS_VALID_CTR_KEY_LEN(len) ((((len) == 16) || ((len) == 32) || \
+	((len) == 48)) ? 1 : 0)
+
 /* Function declarations and documenation */
 
 /**