[PATCH -next] net/phy: fix phy_bcm_nsp_usb3.c build and kconfig

[Randy Dunlap]

From: Randy Dunlap <rdun...@infradead.org>

This driver uses mdio* (PHYLIB) interfaces, so it should select
PHYLIB. PHYLIB depends on NETDEVICES to this driver should also
depend on NETDEVICES.

Fixes these build errors:

drivers/built-in.o: In function `nsp_usb3_phy_init':
phy-bcm-nsp-usb3.c:(.text+0x42d8): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x42f4): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x4310): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x432c): undefined reference to `mdiobus_write'
phy-bcm-nsp-usb3.c:(.text+0x4348): undefined reference to `mdiobus_write'
drivers/built-in.o:phy-bcm-nsp-usb3.c:(.text+0x437a): more undefined references 
to `mdiobus_write' follow
drivers/built-in.o: In function `mdio_module_init':
phy-bcm-nsp-usb3.c:(.init.text+0x1e1): undefined reference to 
`mdio_driver_register'
drivers/built-in.o: In function `mdio_module_exit':
phy-bcm-nsp-usb3.c:(.exit.text+0xae): undefined reference to 
`mdio_driver_unregister'

Signed-off-by: Randy Dunlap <rdun...@infradead.org>
Cc: Yendapally Reddy Dhananjaya Reddy <yendapally.re...@broadcom.com>
---
 drivers/phy/Kconfig |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- linux-next-20170130.orig/drivers/phy/Kconfig
+++ linux-next-20170130/drivers/phy/Kconfig
@@ -504,8 +504,9 @@ 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 && (ARCH_BCM_NSP || COMPILE_TEST) && NETDEVICES
        select GENERIC_PHY
+       select PHYLIB
        default ARCH_BCM_NSP
        help
          Enable this to support the Broadcom Northstar plus USB3 PHY.