icnss: Add support for early assert indication

When there is a FW assert, icnss receives the PD down
notification only after the PD dump is pushed to the filesystem.
And if there is a delay in pushing the dump, the notification is
delayed as well, that could result in various timeout in WLAN host
without knowing that FW is already asserted. So add support to send
FW assert early indication to host thru smp2p channel.

CRs-Fixed: 2185226
Change-Id: I470f17a31ae05685e7e3a4701b32ff792e14677e
Signed-off-by: Sameer Thalappil <sameert@codeaurora.org>