MEDIUM: ssl: Add ktls support for AWS-LC.

MEDIUM: ssl: Add ktls support for AWS-LC.

Add ktls support for AWS-LC. As it does not know anything
about ktls, it means extracting keys from the ssl lib, and provide them
to the kernel. At which point we can use regular recvmsg()/sendmsg()
calls.
This patch only provides support for TLS 1.2, AWS-LC provides a
different way to extract keys for TLS 1.3.
Note that this may work with BoringSSL too, but it has not been tested.