dt-bindings: dmaengine: qcom: gpi: add compatible for sm8250

No functional changes, just adding a new compatible for a different
SoC.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210614235358.444834-1-konrad.dybcio@somainline.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>