Hi,

this patch is an attempt to share H4 and BCSP proto for other drivers
than hci_uart.

hci_h4.c and hci_bcsp.c where expecting a hci_uart structure, I define a
more generic one. I need to add a tx_wakeup function for BCSP.

I also added 1 operation henqueue that queue a skb in the head of the
skb list for driver that can't send all the skb data in one operation.

This is far from perfect (I don't like the hci_dev pointer duplication,
...) and untested for hci_uart driver.

Any comments will be appreciated.

Thanks,

Matthieu