Phonet: Implement Pipe Controller to support Nokia Slim Modems

Phonet stack assumes the presence of Pipe Controller, either in Modem or
on Application Processing Engine user-space for the Pipe data.
Nokia Slim Modems like WG2.5 used in ST-Ericsson U8500 platform do not
implement Pipe controller in them.
This patch adds Pipe Controller implemenation to Phonet stack to support
Pipe data over Phonet stack for Nokia Slim Modems.

Signed-off-by: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/phonet/Kconfig b/net/phonet/Kconfig
index 6ec7d55..901956a 100644
--- a/net/phonet/Kconfig
+++ b/net/phonet/Kconfig
@@ -14,3 +14,14 @@
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called phonet. If unsure, say N.
+
+config PHONET_PIPECTRLR
+	bool "Phonet Pipe Controller"
+	depends on PHONET
+	default N
+	help
+	  The Pipe Controller implementation in Phonet stack to support Pipe
+	  data with Nokia Slim modems like WG2.5 used on ST-Ericsson U8500
+	  platform.
+
+	  If unsure, say N.