drm/aspeed: move to devm_platform_ioremap_resource() usage

Replace platform_get_resource + devm_ioremap_resource
with just devm_platform_ioremap_resource()

Used Coccinelle to do this change. SmPl patch:
@rule_1@
identifier res;
expression ioremap_res;
identifier pdev;
@@
-struct resource *res;
...
-res = platform_get_resource(pdev,...);
-ioremap_res = devm_ioremap_resource(...);
+ioremap_res = devm_platform_ioremap_resource(pdev,0);

Cc: Joel Stanley <[e-mail]>
Acked-by: Andrew Jeffery <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Signed-off-by: Anusha Srivatsa <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maxime Ripard <[e-mail]>

drivers/gpu/drm/aspeed/aspeed_gfx_drv.c

···
 	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 	struct device_node *np = pdev->dev.of_node;
 	const struct aspeed_gfx_config *config;
-	struct resource *res;
 	int ret;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	priv->base = devm_ioremap_resource(drm->dev, res);
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);