imx31: fix parent clock for rtc
imx31: fix parent clock for rtc

According to imx31 reference manual the signal from external low
frequency clock is sent to RTC clock.
The patch makes redundant the previously defined mxc_rtc clock.

Signed-off-by: Vladimir Zapolskiy <db9c790829dcb458d3bf76afc103e85be10d8afc@gmail.com>
Cc: Sascha Hauer <c00cbc2b736c26791a3822db86f8796fe9efff67@pengutronix.de>
Cc: Daniel Mack <3d0f3b9ddcacec30c4008c5e030e6c13a478cb4f@caiaq.de>
Signed-off-by: Sascha Hauer <c00cbc2b736c26791a3822db86f8796fe9efff67@pengutronix.de>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs