dt-bindings: bluetooth: qcom,wcn6750-bt: Split to separate schema

dt-bindings: bluetooth: qcom,wcn6750-bt: Split to separate schema

One big Qualcomm Bluetooth schema is hardly manageable: it lists all
possible properties (19 supplies).  Split qcom,wcn6750-bt to separate
bindings, so device schema will be easier to read/maintain and list only
relevant properties.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>