cnss2: Decouple WLAN host driver and PCI/MHI for suspend/resume

Decouple WLAN host driver suspend/resume and PCI link and MHI
suspend/resume so that PCI link and MHI can be suspended/resumeed
separately without WLAN host driver.

Change-Id: I82cb7b8b54c61657c5d0bbaead0ffc1c55ecee8d
Signed-off-by: Yue Ma <yuem@codeaurora.org>