Update DMA check for surface_acpi

Linux upstream commit 5ba846b1ee0792f5a596b9b0b86d6e8cdebfab06 changed
some behavior in dmaengine, this is a fix for that.

patches/4.19/0001-surface-acpi.patch

@@ -1595,7 +1595,7 @@ index 000000000000..ab793f6774a0
 +static bool surfacegen5_idma_filter(struct dma_chan *chan, void *param)
 +{
 +	// see dw8250_idma_filter
-+	return param == chan->device->dev->parent;
++	return param == chan->device->dev;
 +}
 +
 +static int surfacegen5_ssh_check_dma(struct serdev_device *serdev)

patches/5.1/0001-surface-acpi.patch

@@ -1574,7 +1574,7 @@ index 000000000000..ab793f6774a0
 +static bool surfacegen5_idma_filter(struct dma_chan *chan, void *param)
 +{
 +	// see dw8250_idma_filter
-+	return param == chan->device->dev->parent;
++	return param == chan->device->dev;
 +}
 +
 +static int surfacegen5_ssh_check_dma(struct serdev_device *serdev)