[PATCH] phy: fix build error in phy-bcm-nsp-usb3 with COMPILE_TEST

[Tobias Regnery <tobias.regnery@gmail.com>]

I see the following build error with COMPILE_TEST on randconfig builds:

divers/built-in.o: In function `nsp_usb3_phy_init':
phy-bcm-nsp-usb3.c:(.text+0x4050): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x406c): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x4088): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x40a4): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x40c0): undefined reference to `mdiobus_write'
drivers/built-in.o:phy-bcm-nsp-usb3.c:(.text+0x40f2): more undefined references to `mdiobus_write' follow
drivers/built-in.o: In function `mdio_module_init':
phy-bcm-nsp-usb3.c:(.init.text+0x134): undefined reference to `mdio_driver_register'
drivers/built-in.o: In function `mdio_module_exit':
phy-bcm-nsp-usb3.c:(.exit.text+0xcc): undefined reference to `mdio_driver_unregister'

Fix this by adding the correct Kconfig dependency.

Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
---
 drivers/phy/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index dc5277ad1b5a..10e06f0f1dce 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -512,7 +512,7 @@ config PHY_MESON8B_USB2
 
 config PHY_NSP_USB3
 	tristate "Broadcom NorthStar plus USB3 PHY driver"
-	depends on OF && (ARCH_BCM_NSP || COMPILE_TEST)
+	depends on OF && OF_MDIO && (ARCH_BCM_NSP || COMPILE_TEST)
 	select GENERIC_PHY
 	default ARCH_BCM_NSP
 	help
-- 
2.11.0