dmaengine: tegra: Fix build error without IOMMU_API

dmaengine: tegra: Fix build error without IOMMU_API

drivers/dma/tegra186-gpc-dma.c: In function ‘tegra_dma_probe’:
drivers/dma/tegra186-gpc-dma.c:1364:24: error: ‘struct iommu_fwspec’ has no member named ‘ids’
  stream_id = iommu_spec->ids[0] & 0xffff;
                        ^~

Make TEGRA186_GPC_DMA depends on IOMMU_API to fix this.

Fixes: ee17028009d4 ("dmaengine: tegra: Add tegra gpcdma driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20220505093236.15076-1-yuehaibing@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>