socket: introduce osmo_sock_init_osa & osmo_sock_init_osa_ofd

osmo_sock_init_osa() takes osmo_sockaddr* as local and remote endpoints
to setup a socket.

Change-Id: I1eece543e3241ef0e095eb63bb831f7c15a16794
diff --git a/tests/socket/socket_test.err b/tests/socket/socket_test.err
index 0f0f8da..3c198ac 100644
--- a/tests/socket/socket_test.err
+++ b/tests/socket/socket_test.err
@@ -2,3 +2,7 @@
 invalid: you have to specify either BIND or CONNECT flags
 Unable to find a common protocol (IPv4 or IPv6) for local host: 127.0.0.1 and remote host: ::1.
 Unable to find a common protocol (IPv4 or IPv6) for local host: ::1 and remote host: 127.0.0.1.
+invalid: you have to specify either BIND or CONNECT flags
+invalid: the family for local and remote endpoint must be same.
+invalid: the family for local and remote endpoint must be same.
+invalid: the family for local and remote endpoint must be same.