FMC: add a software mezzanine driver

This simple do-nothing mezzanine driver shows how to write a mezzanine
driver, that can also handle interrupts reported by the carrier.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Juan David Gonzalez Cobas <dcobas@cern.ch>
Acked-by: Emilio G. Cota <cota@braap.org>
Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/fmc/Kconfig b/drivers/fmc/Kconfig
index 505e96b..7eacef9 100644
--- a/drivers/fmc/Kconfig
+++ b/drivers/fmc/Kconfig
@@ -25,4 +25,11 @@
 	  that can be rewritten at run time and usef for matching
 	  mezzanines.
 
+config FMC_TRIVIAL
+	tristate "FMC trivial mezzanine driver (software testing)"
+	help
+	  This is a fake mezzanine driver, to show how FMC works and test it.
+	  The driver also handles interrupts (we used it with a real carrier
+	  before the mezzanines were produced)
+
 endif # FMC