In firmware dumps, currently all kinds of key material may be
included, e.g. in host commands (if firmware crashes during the
processing of a key-related command) or in the TX FIFO(s) if
we have been using in-TX-command key material.

Additionally, some firmware versions will advertise sections
of their internal data to not dump, due to them containing some
sensitive data.

Add some infrastructure to allow scrubbing this data out, as
dependent on the opmode's idea of what will need to be done.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211017123741.360cc8fe55b1.Ie3bd3ece38043969f7e116e61a6ec1197a58d78b@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>