Bluetooth: hci_qca: Fix BT not getting powered-off on rmmod

The BT core skips calling the hci_dev's shutdown method when the HCI
is unregistered. This means that qca_power_off() was not getting called
leaving BT powered on.

This causes regulators / pwrseq providers to not get disabled which also
causes problem when re-loading the module because regulators and pwrseq
providers have an enablecount which now has never dropped to 0, causing
the BT to not get properly reset between rmmod and re-load which causes
initialization failure on the re-load.

Fix this by calling qca_power_off() from qca_close() when BT has not
already been powered off through a qca_hci_shutdown() call.

hci_ldisc.c will call qca_close() after freeing the hdev, so this
means that qca_power_off() can now no longer deref hu->hdev, change
the logging in qca_power_off() to no longer use hu->hdev.

Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>