Change cipher suite defaults to modern

This commit changes the defaults to using Mozilla modern
recommendations, and disables TLS1.2 support.  This should be a noop for
almost all uses, as any modern OS has had support for this cipher suite
for a very long time.  Mozilla intermediate is added still as a compile
time fallback in case some clients are impacted, but expectation is that
this is only a security increase for any client new enough to be worth
caring about.[1]

Tested:

Ran testssl.sh, and verified that the appropriate cipher suites and TLS
versions reported.

[1] https://caniuse.com/tls1-3

Change-Id: I31e51fabaa08e01d095035896a59b375b2e336f0
Signed-off-by: Ed Tanous <etanous@nvidia.com>