regulator: qpnp-labibb: add support for touch-to-wakeup feature

There is a requirement to configure LAB/IBB module registers with
the specified settings to enable support for touch-to-wakeup(TTW)
mode. Add support for TTW mode by configuring the LAB/IBB
registers as per the hardware documentation. This feature can be
enabled by specifying qcom,qpnp-labibb-touch-to-wake-en property.

TTW mode settings will be applied to LAB/IBB module registers
when the regulator suspend callback is executed. Normal mode
settings will be restored back when the regulator resume callback
is executed.

CRs-Fixed: 847094
Change-Id: Ia80f0d67de4af701d89fb8dceae80fba078dd367
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>