configure: support target dependent linking

configure: support target dependent linking

This patch is the first attempt to make configure more intelligent with
regard to how it links to libraries. It divides the softmmu libraries into
two lists, a general one and a list which depends on the target
architecture.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>