Documentation: bindings: k3dma: Extend the k3dma driver binding to support hisi-asp

Extend the k3dma driver binding to support hisi-asp hardware
variants.

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Zhuangluan Su <suzhuangluan@hisilicon.com>
Cc: Tanglei Han <hantanglei@huawei.com>
Cc: Ryan Grachek <ryan@edited.us>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: dmaengine@vger.kernel.org
Cc: devicetree@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Youlin Wang <wwx575822@notesmail.huawei.com>
Signed-off-by: Tanglei Han <hantanglei@huawei.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>