staging: lustre: add help section of Kconfig config LNET

Include a help section for Kconfig LNET.
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/Kconfig

 config LNET
-	tristate "Lustre networking subsystem"
+	tristate "Lustre networking subsystem (LNet)"
 	depends on LUSTRE_FS
+	help
+	  The Lustre network layer, also known as LNet, is a networking abstaction
+	  level API that was initially created to allow Lustre Filesystem to utilize
+	  very different networks like tcp and ib verbs in a uniform way. In the
+	  case of Lustre routers only the LNet layer is required. Lately other
+	  projects are also looking into using LNet as their networking API as well.
 
 config LNET_MAX_PAYLOAD
 	int "Lustre lnet max transfer payload (default 1MB)"