Bug fixes for Qualcomm BT chip wcn3990

[Balakrishna Godavarthi <bgodavar@codeaurora.org>]

The below issues are found in the recent testing.

1. Observed device is not going into off state or not responding.
    As wcn3990 require a power pulses to turn on the irrespctive of
    igniting regulators, it was observed that power on or power off
    pulses are not in sync with respective to chip.
    The below patch will help us to wait until byte is pushed on to wires. 		 

    * Bluetooth: hci_qca: use wait_until_sent() for power pulses

2. Observed Chip responding when we are in sleep.
   This is due to turn on flow control during change baudrate request.
   The below patch will only pull the RTS line high instead of turning off
   the flow.

   * Bluetooth: hci_qca: Pull RTS line high for baudrate change command.


3. Observed stray bytes observed after hdev->shutdown.
   Qualcomm bt chip wcn3990, will turn of regulators when hci down.
   This is via hdev->shutdown(), once hdev->shutdown() is called,
   it is not required to send reset command.

   * Bluetooth: hci_qca: clear HCI_QUIRK_RESET_ON_CLOSE flag.

4. Frame reassembly errors splashing on console.
   wcn3990 requires will use multiple baudrates during booting stage.
   i.e. 2400 bps while sending power off pulse
	115200 bps while sending power on pulse
	port close
	port open
	set baudrate to 115200 request the chip version.

  during above process, we are seeing some stray bytes coming up
  on the UART Rx FIFO it could be due to frequent baudrate change.

  This patch will stop the frame reassembly errors.

  * Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

Note: 
   This patches are on top of below patches posted in patch work for hci_qca
   https://lore.kernel.org/patchwork/patch/1005631/
   https://lore.kernel.org/patchwork/patch/1004372/
    

Balakrishna Godavarthi (4):
  Bluetooth: hci_qca: use wait_until_sent() for power pulses
  Bluetooth: hci_qca: Pull RTS line high for baudrate change command
  Bluetooth: hci_qca: clear HCI_QUIRK_RESET_ON_CLOSE flag
  Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

 drivers/bluetooth/hci_qca.c | 66 +++++++++++++++++++++++--------------
 1 file changed, 41 insertions(+), 25 deletions(-)

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