msm: pm-8x60: Merge msm_pm_idle_prepare into msm_pm_idle_enter

Modify LPM drivers to call msm_pm_idle_enter when idle. enter_sleep will
look at available time to sleep and the latencies of different low power
modes and decide the low power mode to enter. It returns the low power
mode enumeration back to cpuidle.

Change-Id: Ide88761aa2954b7d4129b1f5c497374773679012
Signed-off-by: Priyanka Mathur <pmathur@codeaurora.org>
4 files changed