Add WAIT mode (ARM core clock gating) support to imx6q cpuidle driver.
As WAIT mode is broken on imx6q TO 1.0 and 1.1, it only enables the
support for revision 1.2 with chicken bit set.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Move imx6q_cpuidle_driver into a separate file as more codes will
be added when WAIT mode gets implemented as cpuidle.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>