arm64: dts: qcom: sm8450-nagara: Add Samsung touchscreen

Add device node and required pinctrl settings (as well as a fixup for
an existing one, whoops!) to support the Samsung Electronics
touchscreen on Nagara devices.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221114095654.34561-4-konrad.dybcio@linaro.org