Bluetooth: hci_qca: Make bt_en and susclk not mandatory for QCA Rome

On some platforms the bt_en pin and susclk are default on and there
is no exposed resource to control them. This patch makes the bt_en
and susclk not mandatory to have BT work. It also will not set the
HCI_QUIRK_NON_PERSISTENT_SETUP and shutdown() callback if bt_en is
not available.

Signed-off-by: Rocky Liao <rjliao@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>