net: ftgmac100: depend on NET

FTGMAC100 enables drivers/net/ftgmac100.c which uses
PHY_INTERFACE_MODE_NCSI, which is defined only when PHY_NCSI is enabled.
Therefore FTGMAC100 depends on PHY_NCSI. However adding such a
dependency causes a "recursive dependency detected!" message, so
add a dependency on NET instead (PHY_NCSI depends on NET).
All in all, either the stack is NET and FTGMAC100 can be enabled,
or it is NET_LWIP (or NO_NET) and it cannot.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 6ed3255..e7d0ddf 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -468,6 +468,7 @@
 config FTGMAC100
 	bool "Ftgmac100 Ethernet Support"
 	select PHYLIB
+	depends on NET
 	help
 	  This driver supports the Faraday's FTGMAC100 Gigabit SoC
 	  Ethernet controller that can be found on Aspeed SoCs (which