As per VYBRIDRM.pdf, p. 673:

"... When switching clock sources on GL MUX, both active and target
clock sources must be active..."

So mark all of the clock muxes controlled by CCM_CSSR with
CLK_OPS_PARENT_ENABLE to satisfy that requirement. Experiment shows
that failing to do so would result in failure (in some cases CPU
hang).

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Mask ROM leaves the CPU running at 264Mhz, so configure the clock tree
such that CPU runs at maximum supported frequency. Maximum supported
frequncy is determined from speed grading burned into OCOTP fusebox by
the vendor.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Based on analogous code from Linux kernel

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>