MLK-9678 arm: imx6: switch to analog bypass before entering DSM

MLK-9678 arm: imx6: switch to analog bypass before entering DSM

this patch implements the workaround for ERR005852:

ERR005852 Analog: Transition from Deep Sleep Mode to LDO Bypass
Mode may cause the slow response of the VDDARM_CAP output.

    Normally, the VDDARM_CAP supply takes only approximately 40 us
    to raise to the correct voltage when exiting from Deep Sleep(DSM)
    mode, if the LDO is enabled. If the LDO bypass mode is selected,
    the VDDARM_CAP supply voltage will drop to approximately 0V when
    entering and when exiting from DSM,even though the VDDARM_IN
    supply is already stable, the VDDARM_CAP supply will take about
    2 ms to rise to the correct voltage.

software workaround:

if internal LDO bypass, switch to analog bypass mode(0x1E), prior
to entering DSM, and then, revert to the normal bypass mode, when
exiting from DSM.

Signed-off-by: Bai Ping <b51503@freescale.com>
(cherry picked from commit e43b7ad7c9b8fa987daa539543c5060c97922eb2)