arm64: dts: qcom: sdm845-xiaomi-beryllium-ebbg: introduce touchscreen support

arm64: dts: qcom: sdm845-xiaomi-beryllium-ebbg: introduce touchscreen support

Enable the Focaltech FT8719 touchscreen controller used in the Poco F1
(EBBG) panel variant.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Joel Selvaraj <foss@joelselvaraj.com>
Link: https://lore.kernel.org/r/20250506-pocof1-touchscreen-support-v4-4-bfb53da52945@joelselvaraj.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>