If modem crashed during wlan driver unloading, icnss driver
will call driver uevent callback to set FW down status in
driver side when it receives BEFORE_SHUTDOWN notification.
If wlan driver is de-initialized just before the callback
is called, kernel will panic as driver's context is freed.
This can be avoid by not setting FW status in host driver.
Instead, icnss driver provides an API to host driver to
check FW status and host driver calls this API before any timeout
assert or accessing HW registers.
CRs-Fixed: 2161431
Change-Id: I8331367dd41dd0cedfa65c63f1bb3ffcb535e1c9
e470977e9f