Bluetooth: qca: enable pwrseq support for WCN39xx devices

The WCN39xx family of WiFi/BT chips incorporates a simple PMU, spreading
voltages over internal rails. Implement support for using powersequencer
for this family of QCA devices in addition to using regulators.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>