Add ARM common idle states device bindings for cpuidle support for APQ
8084.

Support Standalone power collapse (SPC) idle state (power down that does not
affect any SoC idle states) for each cpu.
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Olof Johansson <olof@lixom.net>