Bluetooth: hci_h4: Add support for ISO packets in h4_recv.h

This adds ISO packet support in h4_recv.h, which was created before ISO
packet handling was added to hci_h4.c and hci_uart.c

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>