drm/exynos: enable FIMD clocks

Common Clock Framework introduced the need to prepare clocks before
enabling them, otherwise clk_enable() fails. This patch adds clk_prepare_enable
and clk_disable_unprepare() calls to the driver.
This patch also removes clk_disable() from fimd_remove() as it will be done
by pm_runtime_put_sync.

Signed-off-by: Vikas Sajjan <vikas.sajjan@linaro.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_fimd.c

@@ -801,18 +801,18 @@ static int fimd_clock(struct fimd_context *ctx, bool enable)
 	if (enable) {
 		int ret;
 
-		ret = clk_enable(ctx->bus_clk);
+		ret = clk_prepare_enable(ctx->bus_clk);
 		if (ret < 0)
 			return ret;
 
-		ret = clk_enable(ctx->lcd_clk);
+		ret = clk_prepare_enable(ctx->lcd_clk);
 		if  (ret < 0) {
-			clk_disable(ctx->bus_clk);
+			clk_disable_unprepare(ctx->bus_clk);
 			return ret;
 		}
 	} else {
-		clk_disable(ctx->lcd_clk);
-		clk_disable(ctx->bus_clk);
+		clk_disable_unprepare(ctx->lcd_clk);
+		clk_disable_unprepare(ctx->bus_clk);
 	}
 
 	return 0;
@@ -996,9 +996,6 @@ static int fimd_remove(struct platform_device *pdev)
 	if (ctx->suspended)
 		goto out;
 
-	clk_disable(ctx->lcd_clk);
-	clk_disable(ctx->bus_clk);
-
 	pm_runtime_set_suspended(dev);
 	pm_runtime_put_sync(dev);