staging: comedi: ni_labpc: tidy up after DMA code migration

After migrating the ISA DMA handling code to the "ni_labpc_isadma"
module, get rid of an unneeded `#include` and a couple of unused
static variables.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_labpc.c

@@ -65,8 +65,6 @@
 
 #include "../comedidev.h"
 
-#include <asm/dma.h>
-
 #include "8253.h"
 #include "8255.h"
 #include "comedi_fc.h"
@@ -175,11 +173,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 };
 #endif
 
-/* size in bytes of dma buffer */
-static const int dma_buffer_size = 0xff00;
-/* 2 bytes per sample */
-static const int sample_size = 2;
-
 static int labpc_counter_load(struct comedi_device *dev,
 			      unsigned long base_address,
 			      unsigned int counter_number,