dma: only include sof_dma.h when needed

sof_dma.h is only used when actually building SOF. Put it under a
proprocessor conditional to fix including the header in twister
builds.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

zephyr/include/sof/lib/dma.h

@@ -270,9 +270,9 @@ int dmac_init(struct sof *sof);
  * Need to use sof_dma.h to avoid "syscalls/dma.h" name conflict
  * with Zephyr autogenerated headers for syscall support.
  */
+#ifdef CONFIG_ZEPHYR_NATIVE_DRIVERS
 #include "sof_dma.h"
-
-#ifndef CONFIG_ZEPHYR_NATIVE_DRIVERS
+#else
 #include "dma-legacy.h"
 #endif /* !CONFIG_ZEPHYR_NATIVE_DRIVERS */