net: add PPP on PPTP Network Server (PPPoPNS) driver.

Signed-off-by: Chia-chi Yeh <chiachi@android.com>

ppopns: dont include px_proto define in if_pppopns.h

Change-Id: I27e687667db5b45182562f4a517a2e6cec6b1350
Signed-off-by: Dima Zavin <dima@android.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 5abe1b3..a6aad4d 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -3332,6 +3332,14 @@
 	  and a PPP channel, but only permits one session per socket. Thus it is
 	  fairly simple and suited for clients.
 
+config PPPOPNS
+	tristate "PPP on PPTP Network Server"
+	depends on PPP && INET
+	help
+	  PPTP (RFC 2637) is a tunneling protocol widely used in virtual private
+	  networks. This driver handles PPTP data packets between a RAW socket
+	  and a PPP channel. It is fairly simple and easy to use.
+
 config SLIP
 	tristate "SLIP (serial line) support"
 	---help---