dmaengine: dw: Register ACPI DMA controller for PCI that has companion

If PCI enumerated controller has a companion device,
register it in the ACPI DMA controllers as well.

Fixes: f7c799e950f9 ("dmaengine: dw: we do support Merrifield SoC in PCI mode")
Depends-on: b685fe26e9af ("dmaengine: dw: platform: Split ACPI helpers to separate module")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200526182416.52805-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw: platform: Split ACPI helpers to separate module

For better maintenance split ACPI helpers to the separate module.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>