cdx: Enable compile testing

cdx: Enable compile testing

There is no code limited to ARM64 or OF/Devicetree in the CDX bus
driver, so CDX_BUS can be compile tested on all platforms.
CDX_CONTROLLER on the other hand selects REMOTEPROC which depends on
HAS_DMA, so add that dependency for compile testing.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20250502-cdx-clean-v3-1-6aaa5b369fc5@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>