dm ima: prefix dm table hashes in ima log with hash algorithm

The active/inactive table hashes measured in the ima log do not contain
the information about hash algorithm.  This information is useful for the
attestation servers to recreate the hashes and compare them with the ones
present in the ima log to verify the table contents.

Prefix the table hashes in various DM events in ima log with the hash
algorithm used to compute those hashes.

Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>