arm64: dts: qcom: sm8250: drop duplicate memory-region defs

arm64: dts: qcom: sm8250: drop duplicate memory-region defs

The base file, sm8250.dtsi, alread includes memory-region under the
GPU's zap-shader node. Drop duplicates from the individual board files.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20251028-dt-zap-shader-v1-5-7eccb823b986@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>