ASoC: dt-bindings: wcd938x: Add gpio property for selecting CTIA/OMTP headset

Add gpio property used for selecting CTIA/OMTP headset connected
to wcd codec.

Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
Co-developed-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
Signed-off-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
Link: https://lore.kernel.org/r/1644668672-29790-3-git-send-email-quic_srivasam@quicinc.com


Signed-off-by: Mark Brown <broonie@kernel.org>