arm64: dts: apq8096-db820c: Removed bt-en-1-8v regulator

This patch removes the unused bt-en-1-8v regulator and moves the
bt_en_gios claim to the pm8994_gpios node.

This bt_en_gpio could have been moved to the bluetooth serial node but
instead this node declares an 'enable' gpio addressing the bt_en_gpio.
This is needed by the Qualcomm QCA6174 WLAN/BT combo chip that needs to
have the bt_en_gpio claimed even if only WLAN is used.

Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>