Revert "msm: pm: Add support for retention on each core"

This reverts commit 1cc96898b49958d152edacf51309c292215dff4a.

Change-Id: Ib3b0b0b34e652c9e16b5c04efc59399c858da577
Merge "Revert "msm: pm: Add support for retention on each core"" into jb4.2