mfd: Add support for no-interrupt stmpe config

Adds support for boards which have an STMPE device without the
interrupt pin connected.

Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Chris Blair <chris.blair@stericsson.com>
Tested-by: Michel Jaouen <michel.jaouen@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/include/linux/mfd/stmpe.h b/include/linux/mfd/stmpe.h
index ca1d7a34..a1c6aa7 100644
--- a/include/linux/mfd/stmpe.h
+++ b/include/linux/mfd/stmpe.h
@@ -26,6 +26,7 @@
 	STMPE1601,
 	STMPE2401,
 	STMPE2403,
+	STMPE_NBR_PARTS
 };
 
 /*