dmaengine: tegra-apb: Support COMPILE_TEST

There is nothing arch-specific in the driver's code, so let's enable
compile-testing for the driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-18-digetx@gmail.com


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