mako: Enable Krait retention

Adapted from:
commit 4de1d7f5ae9e9da40a6399c5e807cbbc2dc0c17f
Author: Girish Mahadevan <girishm@codeaurora.org>
Date:   Wed Sep 12 14:42:30 2012 -0600

    device/qcom/common: Enable Krait retention

    Enable Krait retention during idle modes.
    Krait retention is a new low power mode supported
    only on core0 on msm8960 based chipsets.

    Change-Id: Ic427f3652e370de022bdfb63c779fb0440f07376
    Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
    (cherry picked from commit 690b2012d03cef7ca1cf8d2ce8cec432b70e01f3)

* required by kernel change

Change-Id: I95f30843e871dba5da8f014e4793abae3d683072