drivers: net: phy: Fix aquantia compilation with DM

With CONFIG_DM_ETH enabled, aquantia driver compilation fails with
below error. This patch fixes the issue by including dm.h.

drivers/net/phy/aquantia.c: In function ‘aquantia_startup’:
drivers/net/phy/aquantia.c:73:21: error: dereferencing pointer to
incomplete
type ‘struct udevice’
          phydev->dev->name);
		     ^~

Signed-off-by: Calvin Johnson <calvin.johnson@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/phy/aquantia.c

@@ -7,6 +7,7 @@
  */
 #include <config.h>
 #include <common.h>
+#include <dm.h>
 #include <phy.h>
 
 #ifndef CONFIG_PHYLIB_10G