clk: ep93xx: Fix off by one in ep93xx_div_recalc_rate()

The psc->div[] array has psc->num_div elements.  These values come from
when we call clk_hw_register_div().  It's adc_divisors and
ARRAY_SIZE(adc_divisors)) and so on.  So this condition needs to be >=
instead of > to prevent an out of bounds read.

Fixes: 9645ccc7 ("ep93xx: clock: convert in-place to COMMON_CLK")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/1caf01ad4c0a8069535813c26c7f0b8ea011155e.camel@linaro.org
[arnd: the original patch was for arch/arm/mach-ep93xx/clock.c,
but the same bug ended up in arch/arm/mach-ep93xx/clock.c.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/clk/clk-ep93xx.c

@@ -383,7 +383,7 @@ static unsigned long ep93xx_div_recalc_rate(struct clk_hw *hw,
 
 	regmap_read(priv->map, clk->reg, &val);
 	index = (val & clk->mask) >> clk->shift;
-	if (index > clk->num_div)
+	if (index >= clk->num_div)
 		return 0;
 
 	return DIV_ROUND_CLOSEST(parent_rate, clk->div[index]);