Bluetooth: Allow HCI UART reset parameter via flags ioctl

The flags ioctl for HCI UART drivers already allows setting of certain
Bluetooth core quirks. The reset parameter fits right in here. So allow
this as well.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Conflicts:

	drivers/bluetooth/hci_ldisc.c

Change-Id: If5c4a6b6dc5f084a79c38de631d136258bf4510d