input: Touchscreen driver for TPS6507x

Add touch screen input driver for TPS6507x family of multi-function
chips.  Uses the TPS6507x MFD driver.  No interrupt support due to
testing limitations of current hardware.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/tps6507x.c b/drivers/mfd/tps6507x.c
index c59f745..d859dff 100644
--- a/drivers/mfd/tps6507x.c
+++ b/drivers/mfd/tps6507x.c
@@ -26,6 +26,9 @@
 	{
 		.name = "tps6507x-pmic",
 	},
+	{
+		.name = "tps6507x-ts",
+	},
 };