MIPS: loongson32: ls1c: Fix hang during startup

The RTCCTRL reg of LS1C is obselete.
Writing this reg will cause system hang.

Fixes: 60219c56 ("MIPS: Add RTC support for Loongson1C board")
Signed-off-by: Yang Ling <gnaygnil@gmail.com>
Tested-by: Keguang Zhang <keguang.zhang@gmail.com>
Acked-by: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/loongson32/ls1c/board.c

@@ -15,7 +15,6 @@ static struct platform_device *ls1c_platform_devices[] __initdata = {
 static int __init ls1c_platform_init(void)
 {
 	ls1x_serial_set_uartclk(&ls1x_uart_pdev);
-	ls1x_rtc_set_extclk(&ls1x_rtc_pdev);
 
 	return platform_add_devices(ls1c_platform_devices,
 				   ARRAY_SIZE(ls1c_platform_devices));