Input: stmpe-ts - add DT support for stmpe touchscreen

This patch allows the STMPE Touchscreen driver to be successfully probed and
initialised when Device Tree support is enabled. Bindings are mentioned in
Documentation too.

Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index c94f521..55c7b95 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -411,6 +411,7 @@
 
 static struct mfd_cell stmpe_ts_cell = {
 	.name		= "stmpe-ts",
+	.of_compatible	= "st,stmpe-ts",
 	.resources	= stmpe_ts_resources,
 	.num_resources	= ARRAY_SIZE(stmpe_ts_resources),
 };