dmaengine: tegra: Remove unused switch case

Remove unused switch case in get_transfer_param() function.
The function is not called for MEM_TO_MEM transfers.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Link: https://lore.kernel.org/r/20220426101913.43335-3-akhilrajeev@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>