dma: tegra: make data used as *of_device_id.data const

Since of_device_id.data is declared as a pointer to const data a few
more consts can be added in this driver.

[ukl: split Laxman's patch to prevent warnings in the middle of the
series. Original patch was sent with msgid
1346217447-19730-1-git-send-email-ldewangan@nvidia.com]

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/dma/tegra20-apb-dma.c

@@ -1166,14 +1166,14 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
 }
 
 /* Tegra20 specific DMA controller information */
-static struct tegra_dma_chip_data tegra20_dma_chip_data = {
+static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
 	.nr_channels		= 16,
 	.max_dma_count		= 1024UL * 64,
 };
 
 #if defined(CONFIG_OF)
 /* Tegra30 specific DMA controller information */
-static struct tegra_dma_chip_data tegra30_dma_chip_data = {
+static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
 	.nr_channels		= 32,
 	.max_dma_count		= 1024UL * 64,
 };