Internal clock path handling for the mxc CPUs.
Changed against the original Freescale code (and against clocklib for example):
- clock rate is always calculated whenever one ask for the current rate
(means struct clk has no more a member called "rate"). So switching the PLL
base frequency will propagate immediately to all other clocks that are
depending on this frequency.
Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>
