dma: pl08x: Export pl08x_filter_id

Export the symbol so that it is accessible to modules.
Fixes the following error:
ERROR: "pl08x_filter_id" [sound/soc/samsung/snd-soc-s3c-dma.ko] undefined!
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/amba-pl08x.c

@@ -83,6 +83,7 @@
 #include <linux/dmaengine.h>
 #include <linux/dmapool.h>
 #include <linux/dma-mapping.h>
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
@@ -1771,6 +1772,7 @@ bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
 
 	return false;
 }
+EXPORT_SYMBOL_GPL(pl08x_filter_id);
 
 /*
  * Just check that the device is there and active