net: e1000: Depend on CONFIG_PCI

This driver depends on PCI. Update the Kconfig accordingly.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 7fe0e00..84d859c 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -231,6 +231,7 @@
 
 config E1000
 	bool "Intel PRO/1000 Gigabit Ethernet support"
+	depends on PCI
 	help
 	  This driver supports Intel(R) PRO/1000 gigabit ethernet family of
 	  adapters.  For more information on how to identify your adapter, go