arm64: dts: qcom: sm8150: Don't start Adreno in headless mode

arm64: dts: qcom: sm8150: Don't start Adreno in headless mode

Now that there's display support, there is no reason to assume the default
mode for Adreno should be headless. Keep it like that for boards that
previously enabled it, so as not to create regressions though.

Tested-by: Marijn Suijten <marijn.suijten@somainline.org> # On Sony Xperia 5
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230331-topic-konahana_speedbin-v3-3-2dede22dd7f7@linaro.org