iio: buffer-dmaengine: Add module information

Make sure that the industrialio-buffer-dmaengine has proper license
information so it can be build as a module and loaded without tainting the
kernel.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/buffer/industrialio-buffer-dmaengine.c

@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/spinlock.h>
 #include <linux/err.h>
+#include <linux/module.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
@@ -206,3 +207,7 @@ void iio_dmaengine_buffer_free(struct iio_buffer *buffer)
 	iio_buffer_put(buffer);
 }
 EXPORT_SYMBOL_GPL(iio_dmaengine_buffer_free);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("DMA buffer for the IIO framework");
+MODULE_LICENSE("GPL");