soc: qcom: msm_glink_pkt: Register and wait for link up notification

The user space clients sometimes open the device before the underlying
transport available which results in open error and cause multiple re-tries
from the clients. This leads to excessive logging of open error messages.

Register for link state notification and block the client open until link
available or user define timer expires.

CRs-Fixed: 1018542
Change-Id: I4e56982700f3444f96e1100c0ce272d36d3423a5
Signed-off-by: Dhoat Harpal <hdhoat@codeaurora.org>