GCM: compressed GCM key structure by 144 bytes (9 blocks)

- created separate files to define key structure for different architecture
  implementations
- SSE/AVX needs 8 hash keys for schoolbook and karatsuba multiply
- AVX2/AVX512 needs only 8 hash keys for schoolbook multiply
- VAES AVX512 needs only 48 or 128 hash keys for schoolbook multiply
- 16 byte padding between AES keys and hash keys removed

Change-Id: I58dc8612cd52dce8c15af3285834b9f58b9f7b07