mfd: Fix missing stmpe kerneldoc

Generating kerneldoc for STMPE result in warnings, so fix this by
adding missing documentation.

Signed-off-by: Om Prakash <omprakash.pal@stericsson.com>
Reviewed-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index 7ab77466..2963689c 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -228,7 +228,7 @@
 EXPORT_SYMBOL_GPL(stmpe_block_write);
 
 /**
- * stmpe_set_altfunc: set the alternate function for STMPE pins
+ * stmpe_set_altfunc()- set the alternate function for STMPE pins
  * @stmpe:	Device to configure
  * @pins:	Bitmask of pins to affect
  * @block:	block to enable alternate functions for