Bluetooth: EWS: define L2CAP header sizes

Adds definitins for L2CAP header sizes to be uses when calculating
payload size instead of magic numbers.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 67a2fdb..806b950 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -162,6 +162,12 @@
 	__le16     cid;
 } __packed;
 #define L2CAP_HDR_SIZE		4
+#define L2CAP_ENH_HDR_SIZE	6
+#define L2CAP_EXT_HDR_SIZE	8
+
+#define L2CAP_FCS_SIZE		2
+#define L2CAP_SDULEN_SIZE	2
+#define L2CAP_PSMLEN_SIZE	2
 
 struct l2cap_cmd_hdr {
 	__u8       code;