Add the necessary pinctrl, interrupt property and a suitable sleep config
to support Bluetooth wakeup feature.

GPIO mode is configured in sleep state to drive the RTS/RFR line low.
If QUP function is selected in sleep state, UART RTS/RFR is pulled high
during suspend and BT SoC not able to send wakeup bytes.
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: satya priya <skakit@codeaurora.org>
Link: https://lore.kernel.org/r/1600091917-7464-4-git-send-email-skakit@codeaurora.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>