cnss2: Add platform driver code to handle hang event data

On SSR, FW writes hang data in the carved out region from
existing DDR memory, the platform driver copies the hang
event data from the fixed offset to local buffer and sends
the buffer and length to host driver via CNSS_HANG_EVENT
event.

Change-Id: I5928821770086547b4fe17c30a967ea059b39394
Signed-off-by: Mohammed Siddiq <msiddiq@codeaurora.org>