cnss2: Dump debug registers for firmware assert

There are possibilities that firmware RAM dump collection is stuck
due to MHI in bad state. Dump debug registers to help debug these
issues.

Change-Id: Iae7ec4b21146d5dc6d78df77b87afd7fd00ef5e5
Signed-off-by: Yue Ma <yuem@codeaurora.org>