arm64: dts: qcom: msm8916-wingtech-wt88047: Add touchscreen

The Xiaomi Redmi 2 has a FocalTech touchscreen. The exact model is
not mentioned anywhere, but it works just fine with the mainline
edt-ft5x06 driver when using the "edt,edt-ft5506" compatible.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210712133735.318250-2-stephan@gerhold.net


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>