[PATCH] net: wangxun: fix LIBWX dependencies

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Selecting LIBWX requires that its dependencies are met first:

WARNING: unmet direct dependencies detected for LIBWX
  Depends on [m]: NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_WANGXUN [=y] && PTP_1588_CLOCK_OPTIONAL [=m]
  Selected by [y]:
  - TXGBE [=y] && NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_WANGXUN [=y] && PCI [=y] && COMMON_CLK [=y] && I2C_DESIGNWARE_PLATFORM [=y]
ld.lld-21: error: undefined symbol: ptp_schedule_worker
>>> referenced by wx_ptp.c:747 (/home/arnd/arm-soc/drivers/net/ethernet/wangxun/libwx/wx_ptp.c:747)
>>>               drivers/net/ethernet/wangxun/libwx/wx_ptp.o:(wx_ptp_reset) in archive vmlinux.a

Add the smae dependency on PTP_1588_CLOCK_OPTIONAL to the two driver
using this library module.

Fixes: 06e75161b9d4 ("net: wangxun: Add support for PTP clock")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/ethernet/wangxun/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/wangxun/Kconfig b/drivers/net/ethernet/wangxun/Kconfig
index 6b60173fe1f5..47e3e8434b9e 100644
--- a/drivers/net/ethernet/wangxun/Kconfig
+++ b/drivers/net/ethernet/wangxun/Kconfig
@@ -26,6 +26,7 @@ config LIBWX
 config NGBE
 	tristate "Wangxun(R) GbE PCI Express adapters support"
 	depends on PCI
+	depends on PTP_1588_CLOCK_OPTIONAL
 	select LIBWX
 	select PHYLINK
 	help
@@ -43,6 +44,7 @@ config TXGBE
 	depends on PCI
 	depends on COMMON_CLK
 	depends on I2C_DESIGNWARE_PLATFORM
+	depends on PTP_1588_CLOCK_OPTIONAL
 	select MARVELL_10G_PHY
 	select REGMAP
 	select PHYLINK
-- 
2.39.5