The imx6 hardware is fast enough to make good use of however much
timecounter resolution is available, so ask for a 1 GHz frequency.  It
won't actually get one that fast, but that'll get the fastest available
clock and use a divisor of 1 (probably 132 or 66mhz on current hardware).
Attach the imx6 CCM driver during BUS_PASS_CPU.  It controls the clocks
for most on-chip devices and needs to be available before other drivers
start attaching and asking to have their clocks enabled.