Bluetooth: hci_uart: Fix speed selection

hu->proto->*speed will always be used for all device where it is set.
But hu->*speed should be used if exist, so the test should be swapped.

The equivalent change is needed in bcm_setup() of hci_bcm.c.

Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>