rapidio: add debug configuration option

Add debug configuration option for RapidIO subsystem.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rapidio/Kconfig b/drivers/rapidio/Kconfig
index bcb5c20..070211a 100644
--- a/drivers/rapidio/Kconfig
+++ b/drivers/rapidio/Kconfig
@@ -21,3 +21,14 @@
 	  than Maintenance transfers.
 
 source "drivers/rapidio/switches/Kconfig"
+
+config RAPIDIO_DEBUG
+	bool "RapidIO subsystem debug messages"
+	depends on RAPIDIO
+	help
+	  Say Y here if you want the RapidIO subsystem to produce a bunch of
+	  debug messages to the system log. Select this if you are having a
+	  problem with the RapidIO subsystem and want to see more of what is
+	  going on.
+
+	  If you are unsure about this, say N here.