drm/exynos: use DIV_ROUND_CLOSEST to find the closest div

This patch uses DIV_ROUND_CLOSEST instead of DIV_ROUND_UP
The DIV_ROUND_CLOSEST can be used to find the closest integer
value when we divide some integers.

Signed-off-by: Chanho Park <[e-mail]>
Signed-off-by: Inki Dae <[e-mail]>

drivers/gpu/drm/exynos/exynos_drm_fimd.c

···
 	}
 
 	/* Find the clock divider value that gets us closest to ideal_clk */
-	clkdiv = DIV_ROUND_UP(clk_get_rate(ctx->lcd_clk), ideal_clk);
+	clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(ctx->lcd_clk), ideal_clk);
 
 	return (clkdiv < 0x100) ? clkdiv : 0xff;
 }