Fix some invalid config options.

INET_AH, INET6_AH - These options are never used and not tested
INET_MODE_XFRM, TRANSPORT - Option string had become split. Merged.
CRYPTO_SHA12 - Not a valid kernel option. SHA512 is specified below.
CRYPTO_SHA256 - Duplicate definition removed.

Bug: 79546208
Change-Id: I954791bd764dc6f7d19ae1dfda66a29aede83245
Signed-off-by: Alistair Strachan <astrachan@google.com>