hw/alpha/dp264: Include "net/net.h"

hw/alpha/dp264: Include "net/net.h"

hw/alpha/dp264.c uses NICInfo variables which are declared in
"net/net.h". Include it.

This fixes (when modifying unrelated headers):

  hw/alpha/dp264.c:89:21: error: use of undeclared identifier 'nb_nics'
      for (i = 0; i < nb_nics; i++) {
                      ^
  hw/alpha/dp264.c:90:30: error: use of undeclared identifier 'nd_table'
          pci_nic_init_nofail(&nd_table[i], pci_bus, "e1000", NULL);
                               ^

Acked-by: John Snow <jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200228114649.12818-9-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>