goldfish: pipe: ANDROID: Add DMA support

This change improves the pipe performance by removing unnesessary
memory copying.

Bug: 72717639
Bug: 66884503
Change-Id: I0d279f682039e411faf4212713d82ec355c3e9ee
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Lingfeng Yang <lfy@google.com>

Author: Roman Kiryanov

drivers/platform/goldfish/goldfish_pipe.h

@@ -87,6 +87,9 @@ struct goldfish_pipe_dev {
 
 	/* ptr to platform device's device struct */
 	struct device *pdev_dev;
+
+	/* DMA info */
+	size_t dma_alloc_total;
 };
 
 extern struct goldfish_pipe_dev goldfish_pipe_dev;