dt-bindings: dmaengine: qcom: gpi: add compatible for sm8150

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

Signed-off-by: Felipe Balbi <felipe.balbi@microsoft.com>
Link: https://lore.kernel.org/r/20210417061951.2105530-2-balbi@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>