sunxi: restore PHYLIB for CONFIG_SUN4I_EMAC users

due misnaming of CONFIG_SUN4I_EMAC in include/configs/sunxi-common.h,
likely missed in:
	commit 3146f0c0 ("Move PHYLIB to Kconfig")
Signed-off-by: NArtturi Alm <artturi.alm@gmail.com>
Reviewed-by: NJagan Teki <jagan@openedev.com>

drivers/net/Kconfig

@@ -247,6 +247,7 @@ config SUN7I_GMAC
 config SUN4I_EMAC
 	bool "Allwinner Sun4i Ethernet MAC support"
 	depends on DM_ETH
+	select PHYLIB
 	help
 	  This driver supports the Allwinner based SUN4I Ethernet MAC.