net: phy: bcm63xx: Allow to be built with COMPILE_TEST

There is nothing in this driver which prevents it to be compiled for
other architectures. Add COMPILE_TEST so we get better compile test
coverage.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/Kconfig

@@ -240,7 +240,7 @@ config AT803X_PHY
 
 config BCM63XX_PHY
 	tristate "Broadcom 63xx SOCs internal PHY"
-	depends on BCM63XX
+	depends on BCM63XX || COMPILE_TEST
 	select BCM_NET_PHYLIB
 	---help---
 	  Currently supports the 6348 and 6358 PHYs.