ARM: mach-imx: iomux-imx31: Use DECLARE_BITMAP

Use the generic mechanism to declare a bitmap instead of unsigned long.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/iomux-imx31.c

@@ -40,7 +40,7 @@ static DEFINE_SPINLOCK(gpio_mux_lock);
 
 #define IOMUX_REG_MASK (IOMUX_PADNUM_MASK & ~0x3)
 
-static unsigned long mxc_pin_alloc_map[NB_PORTS * 32 / BITS_PER_LONG];
+static DECLARE_BITMAP(mxc_pin_alloc_map, NB_PORTS * 32);
 /*
  * set the mode for a IOMUX pin.
  */