Add some missing cfi frame info in aesni-gcm-x86_64.S

While preparing #9749 some .cfi_{start,end}proc directives
were missed. Add the missing ones.

See upstream https://github.com/openssl/openssl/commit/275a048f

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes #11101