input: Export matrix_keypad_parse_of_params()

Couple of input drivers depend on this symbol:

ERROR: "matrix_keypad_parse_of_params" [drivers/input/keyboard/tca8418_keypad.ko] undefined!
ERROR: "matrix_keypad_parse_of_params" [drivers/input/keyboard/cros_ec_keyb.ko] undefined!

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/input/matrix-keymap.c b/drivers/input/matrix-keymap.c
index 619b382..08b61f5 100644
--- a/drivers/input/matrix-keymap.c
+++ b/drivers/input/matrix-keymap.c
@@ -68,6 +68,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(matrix_keypad_parse_of_params);
 
 static int matrix_keypad_parse_of_keymap(const char *propname,
 					 unsigned int rows, unsigned int cols,