staging: comedi: dt2801: Prefer using the BIT macro

As suggested by checkpatch.pl, this patch replaces bit shifting on 1 with the
BIT(x) macro.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt2801.c

@@ -68,17 +68,17 @@ Configuration options:
 /* Command modifiers (only used with read/write), EXTTRIG can be
    used with some other commands.
 */
-#define DT_MOD_DMA     (1<<4)
-#define DT_MOD_CONT    (1<<5)
-#define DT_MOD_EXTCLK  (1<<6)
-#define DT_MOD_EXTTRIG (1<<7)
+#define DT_MOD_DMA     BIT(4)
+#define DT_MOD_CONT    BIT(5)
+#define DT_MOD_EXTCLK  BIT(6)
+#define DT_MOD_EXTTRIG BIT(7)
 
 /* Bits in status register */
-#define DT_S_DATA_OUT_READY   (1<<0)
-#define DT_S_DATA_IN_FULL     (1<<1)
-#define DT_S_READY            (1<<2)
-#define DT_S_COMMAND          (1<<3)
-#define DT_S_COMPOSITE_ERROR  (1<<7)
+#define DT_S_DATA_OUT_READY   BIT(0)
+#define DT_S_DATA_IN_FULL     BIT(1)
+#define DT_S_READY            BIT(2)
+#define DT_S_COMMAND          BIT(3)
+#define DT_S_COMPOSITE_ERROR  BIT(7)
 
 /* registers */
 #define DT2801_DATA		0