soc: qcom: glink: Get additional reference in glink open

Inside glink_open reference for channel context is only initialized,
but additional reference is not taken. It creates the possibility of use
after free if SSR happens before glink_open function completes.

Additional reference is taken to ensure context stay valid during
glink_open, even if SSR happens.

CRs-Fixed: 2031123
Change-Id: I94650d2f937416aff33a82073c4db76fab0d0e96
Signed-off-by: Dhoat Harpal <hdhoat@codeaurora.org>