waf-samba.bbclass: move to meta-networking

The recipes that are using waf-samba were all
moved to meta-networking, so move the bbclass
and related cross-answers files as well.

Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>