ARM: shmobile: kzm9g: Fix coherent DMA mask

Commit 4dcfa600 ("ARM: DMA-API: better
handing of DMA masks for coherent allocations") added an additional
check to the coherent DMA mask that results in an error when the mask is
larger than what dma_addr_t can address.

Set the LCDC coherent DMA mask to DMA_BIT_MASK(32) instead of ~0 to fix
the problem.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/board-kzm9g.c

@@ -334,7 +334,7 @@ static struct platform_device lcdc_device = {
 	.resource	= lcdc_resources,
 	.dev	= {
 		.platform_data	= &lcdc_info,
-		.coherent_dma_mask = ~0,
+		.coherent_dma_mask = DMA_BIT_MASK(32),
 	},
 };