dma-buf: dma-heap: export declared functions

Export the dma-buf heap functions to allow them to be used by the OP-TEE
driver. The OP-TEE driver wants to register and manage specific secure
DMA heaps with it.

Reviewed-by: Sumit Garg <[e-mail]>
Reviewed-by: T.J. Mercier <[e-mail]>
Acked-by: Sumit Semwal <[e-mail]>
Signed-off-by: Jens Wiklander <[e-mail]>

drivers/dma-buf/dma-heap.c

···
 #include <linux/dma-buf.h>
 #include <linux/dma-heap.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/list.h>
 #include <linux/nospec.h>
 #include <linux/syscalls.h>
···
 {
 	return heap->priv;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_get_drvdata, "DMA_BUF_HEAP");
 
 /**
  * dma_heap_get_name - get heap name
···
 {
 	return heap->name;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP");
 
 /**
  * dma_heap_add - adds a heap to dmabuf heaps
···
 	kfree(heap);
 	return err_ret;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_add, "DMA_BUF_HEAP");
 
 static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
 {