PublicKey hashes stored in HashStore use hash alg type of
PcdCompSignHash defined with Build config. In container we
support cases where hash type could differ from Sbl default
signing hash.
Adjust the hash algorithm in external KeyHashStore manifest
based on key size. Use SHA256 for size 2K and SHA384 for 3K.
Signed-off-by: Subash Lakkimsetti <subash.lakkimsetti@intel.com>