integritysetup: Add PHMAC algorithm to list of known algorithms

Add the PHMAC integrity algorithm to the list of supported algorithms.

The PHMAC algorithm is like the regular HMAC algorithm, but it takes a wrapped key
as input. A key for the PHMAC algorithm is an opaque key blob, who's physical size
has nothing to do with the cryptographic size. Currently PHMAC is only available
for the s390x architecture.

src/integritysetup/integrity-util.h

@@ -13,4 +13,6 @@ int parse_integrity_options(
 
 #define DM_HMAC_256 "hmac(sha256)"
 #define DM_HMAC_512 "hmac(sha512)"
+#define DM_PHMAC_256 "phmac(sha256)"
+#define DM_PHMAC_512 "phmac(sha512)"
 #define DM_MAX_KEY_SIZE 4096            /* Maximum size of key allowed for dm-integrity */