clk: vt8500: Fix "fix device clock divisor calculations"

Patch 72480014 "Fix device clock divisor calculations" was apparently
rebased incorrectly before it got upstream, causing a build error.

Replacing the "prate" pointer with the local parent_rate is most
likely the correct solution.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Mike Turquette <mturquette@linaro.org>

drivers/clk/clk-vt8500.c

@@ -157,7 +157,7 @@ static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
 	divisor =  parent_rate / rate;
 
 	/* If prate / rate would be decimal, incr the divisor */
-	if (rate * divisor < *prate)
+	if (rate * divisor < parent_rate)
 		divisor++;
 
 	if (divisor == cdev->div_mask + 1)