clk: sunxi: fix some calculations

Some divisor calculations were misrounded, causing higher than requested
rates on some clocks. Fix them up using DIV_ROUND_UP, and replace one
homebrew instance of it as well with the right macro.
Reported-by: Boris BREZILLON <b.brezillon.dev@gmail.com>
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/sunxi/clk-sunxi.c

@@ -299,7 +299,7 @@ static void sun4i_get_apb1_factors(u32 *freq, u32 parent_rate,
 	if (parent_rate < *freq)
 		*freq = parent_rate;
 
-	parent_rate = (parent_rate + (*freq - 1)) / *freq;
+	parent_rate = DIV_ROUND_UP(parent_rate, *freq);
 
 	/* Invalid rate! */
 	if (parent_rate > 32)
@@ -344,7 +344,7 @@ static void sun4i_get_mod0_factors(u32 *freq, u32 parent_rate,
 	if (*freq > parent_rate)
 		*freq = parent_rate;
 
-	div = parent_rate / *freq;
+	div = DIV_ROUND_UP(parent_rate, *freq);
 
 	if (div < 16)
 		calcp = 0;
@@ -385,7 +385,7 @@ static void sun7i_a20_get_out_factors(u32 *freq, u32 parent_rate,
 	if (*freq > parent_rate)
 		*freq = parent_rate;
 
-	div = parent_rate / *freq;
+	div = DIV_ROUND_UP(parent_rate, *freq);
 
 	if (div < 32)
 		calcp = 0;