ux500: Call prmcu_init only for u8500

PRCMU driver only supports u8500. Don't
initialize prcmu if running on u5500.
Signed-off-by: NPer Forlin <per.forlin@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>

arch/arm/mach-ux500/cpu.c

@@ -59,7 +59,8 @@ void __init ux500_init_irq(void)
 	 * Init clocks here so that they are available for system timer
 	 * initialization.
 	 */
-	prcmu_early_init();
+	if (cpu_is_u8500())
+		prcmu_early_init();
 	clk_init();
 }