verilator: use pr_info when compiling cores

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>

Conflicts:
	fusesoc/section/__init__.py
	fusesoc/simulator/verilator.py
verilator: add src_root in included dirs

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>