ARM: dts: qcom-msm8974*: Clean up old GPIO declarations

Remove unneeded level of nesting, as it does not match the current DTS
style.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220415115633.575010-21-konrad.dybcio@somainline.org