dmaengine: ti: unexport filter functions

The two filter functions are now marked static, but still exported,
which triggers a coming build-time check:

WARNING: "omap_dma_filter_fn" [vmlinux] is a static EXPORT_SYMBOL_GPL
WARNING: "edma_filter_fn" [vmlinux] is a static EXPORT_SYMBOL

Remove the unneeded exports as well, as originally intended.

Fixes: 9c71b9eb ("dmaengine: omap-dma: make omap_dma_filter_fn private")
Fixes: d2bfe7b5 ("dmaengine: edma: make edma_filter_fn private")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20190812101155.997721-1-arnd@arndb.deSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/ti/edma.c

@@ -2600,7 +2600,6 @@ static bool edma_filter_fn(struct dma_chan *chan, void *param)
 	}
 	return match;
 }
-EXPORT_SYMBOL(edma_filter_fn);
 
 static int edma_init(void)
 {

drivers/dma/ti/omap-dma.c

@@ -1666,7 +1666,6 @@ static bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
 	}
 	return false;
 }
-EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
 
 static int omap_dma_init(void)
 {