arch: nxp dts bindings: Set IP clock name to matching clock controller

In dts.fixup files for used for NXP SoCs, IP clock name was
bound to SIM clock label. This is correct but would require
manual change if IP clock controller was changed in device tree.
Use reference to IP generated define "_CLOCK_CONTROLLER" to get
this value.

Besides, having all IP related values starting with the same prefix
will be easier for possible macro preprocessing (if required one day).

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>