soc: qcom: Add PMIC Glink driver

The PMIC Glink driver provides the interface for clients to
communicate over GLink for sending and receiving data to charger
firmware that runs on a remote subsystem (e.g. ADSP) which
supports charging and gauging.

This enables clients to read/write battery charging parameters
and get notifications.

Change-Id: I1e4c09d1ee10c8c5397f4459afe8d656593d718a
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>