fpga: m10bmc-sec: expose max10 canceled keys in sysfs

Extend the MAX10 BMC Secure Update driver to provide sysfs files to
expose the 128 bit code signing key (CSK) cancellation vectors. These use
the standard bitmap list format (e.g. 1,2-6,9).

Each CSK is assigned an ID, a number between 0-127, during the signing
process. CSK ID cancellation information is stored in 128-bit fields in
write-once locations in flash.  The cancellation of a CSK can be used
to prevent the card from being rolled back to older images that were
signed with a CSK that is now cancelled.

Reviewed-by: Tom Rix <trix@redhat.com>
Tested-by: Tianfei Zhang <tianfei.zhang@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220606160038.846236-5-russell.h.weight@intel.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>