greybus: svc: skip setting flags for boot over unipro

We need to skip setting E2EFC and other flags to the SVC connection
create request, for all cports, on an interface that need to boot over
unipro, i.e. interfaces required to download firmware.

This also adds a FIXME as we need to do it differently for ES3.

Tested-by: Eli Sennesh <esennesh@leaflabs.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off by: Eli Sennesh <esennesh@leaflabs.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>