soc: qcom: altmode-glink: add SSR support

Add subsystem restart (SSR) support to altmode glink driver so
that when subsystem goes down and comes up again, it can send
PAN_EN to charger firmware to receive notifications about altmode
interface.

Change-Id: Ie011d5110b6c26790fe1dd6149115019f8bc261c
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>