staging: comedi: s626: move struct buffer_dma

Move the declaration of `struct buffer_dma` from "s626.h" to "s626.c" as
it seems more at home there.  After this move, "s626.h" just contains
macros related to hardware registers.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/s626.c

@@ -71,6 +71,11 @@
 #include "comedi_fc.h"
 #include "s626.h"
 
+struct buffer_dma {
+	dma_addr_t physical_base;
+	void *logical_base;
+};
+
 struct s626_private {
 	void __iomem *mmio;
 	uint8_t ai_cmd_running;		/* ai_cmd is running */

drivers/staging/comedi/drivers/s626.h

@@ -614,9 +614,4 @@
 #define STDMSK_CLKMULT		(3 << STDBIT_CLKMULT)
 #define STDMSK_CLKENAB		(1 << STDBIT_CLKENAB)
 
-struct buffer_dma {
-	dma_addr_t physical_base;
-	void *logical_base;
-};
-
 #endif