OMAP: FB: use DMA_BIT_MASK() for fb's coherent_dma_mask

Use DMA_BIT_MASK() for fb's coherent_dma_mask for clarity.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>

arch/arm/plat-omap/fb.c

@@ -29,6 +29,7 @@
 #include <linux/memblock.h>
 #include <linux/io.h>
 #include <linux/omapfb.h>
+#include <linux/dma-mapping.h>
 
 #include <mach/hardware.h>
 #include <asm/mach/map.h>
@@ -45,7 +46,7 @@ static struct platform_device omap_fb_device = {
 	.id		= -1,
 	.dev = {
 		.dma_mask		= &omap_fb_dma_mask,
-		.coherent_dma_mask	= ~(u32)0,
+		.coherent_dma_mask	= DMA_BIT_MASK(32),
 		.platform_data		= &omapfb_config,
 	},
 	.num_resources = 0,
@@ -81,7 +82,7 @@ static struct platform_device omap_fb_device = {
 	.id		= -1,
 	.dev = {
 		.dma_mask		= &omap_fb_dma_mask,
-		.coherent_dma_mask	= ~(u32)0,
+		.coherent_dma_mask	= DMA_BIT_MASK(32),
 		.platform_data		= &omapfb_config,
 	},
 	.num_resources = 0,