ath10k: Enable WoWLAN for the wcn3990 snoc wlan module

Register snoc bus layer suspend/resume PM ops and configure
the wakeup source for the device to adds support for WOWLAN
feature for the wcn3990 snoc wlan module.

CRs-Fixed: 2139961
Change-Id: Ic43414b965aee27564f8bbbe237c706f5262c2e4
Signed-off-by: Sarada Prasanna Garnayak <sgarna@codeaurora.org>