Bluetooth: Add a helper function to extract iso header

Add a helper function hci_iso_hdr() to extract iso header from skb.
Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/hci.h

@@ -2901,6 +2901,11 @@ static inline struct hci_sco_hdr *hci_sco_hdr(const struct sk_buff *skb)
 	return (struct hci_sco_hdr *) skb->data;
 }
 
+static inline struct hci_iso_hdr *hci_iso_hdr(const struct sk_buff *skb)
+{
+	return (struct hci_iso_hdr *)skb->data;
+}
+
 /* Command opcode pack/unpack */
 #define hci_opcode_pack(ogf, ocf)	((__u16) ((ocf & 0x03ff)|(ogf << 10)))
 #define hci_opcode_ogf(op)		(op >> 10)