The mcux sim clock control driver was originally designed to pass
through the clock subsystem value from dts to the mcux CLOCK_GetFreq()
function. This assumed that the values in
include/dt-bindings/clock/kinetis_sim.h matched the enumeration in
fsl_clock.h, which is true for the coresys, platform, and bus clocks.
However, the low-power oscillator (LPO) clock has a different values in
k64 vs. kw2xd, therefore we must update the clock_control driver to
parse the value from dts and convert it to the fsl_clock.h enumeration.
Signed-off-by: Maureen Helm <maureen.helm@nxp.com>