net: systemport: always select FIXED_PHY

There is no need to do the following:

select FIXED_PHY if SYSTEMPORT=y, as this implies that we will not be able
to build and/or run the driver correctly when built as a module, which
is no longer an issue since commit 37e9a690 ("net: phy: export
fixed_phy_register()")

Fixes: a3862db2 ("net: systemport: hook SYSTEMPORT driver in the build")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/Kconfig

@@ -155,7 +155,7 @@ config SYSTEMPORT
 	depends on OF
 	select MII
 	select PHYLIB
-	select FIXED_PHY if SYSTEMPORT=y
+	select FIXED_PHY
 	help
 	  This driver supports the built-in Ethernet MACs found in the
 	  Broadcom BCM7xxx Set Top Box family chipset using an internal