sh: clock-cpg div4 set_rate() shift fix

Make sure the div4 bitfield is shifted according
to the enable_bit value in sh_clk_div4_set_rate().
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/clock-cpg.c

@@ -192,8 +192,8 @@ static int sh_clk_div4_set_rate(struct clk *clk, unsigned long rate, int algo_id
 		return idx;
 
 	value = __raw_readl(clk->enable_reg);
-	value &= ~0xf;
-	value |= idx;
+	value &= ~(0xf << clk->enable_bit);
+	value |= (idx << clk->enable_bit);
 	__raw_writel(value, clk->enable_reg);
 
 	return 0;