systemc: Fix tlm2 socket integration

systemc: Fix tlm2 socket integration

This change will make the systemc extension in gem5 more compatible to
the reference implementation by Accellera.

* Remove the alias of sc_port's bind in initiator socket.
* Ignore -Woverloaded-virtual in initiator socket.

Change-Id: I229e4d493e01d26174c5662ad71d4859d546d307
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23864
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>