Input: mpr121 - switch to use device_property_count_u32()

Use use device_property_count_u32() directly, that makes code neater.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/mpr121_touchkey.c

@@ -253,8 +253,7 @@ static int mpr_touchkey_probe(struct i2c_client *client,
 
 	mpr121->client = client;
 	mpr121->input_dev = input_dev;
-	mpr121->keycount = device_property_read_u32_array(dev, "linux,keycodes",
-							  NULL, 0);
+	mpr121->keycount = device_property_count_u32(dev, "linux,keycodes");
 	if (mpr121->keycount > MPR121_MAX_KEY_COUNT) {
 		dev_err(dev, "too many keys defined (%d)\n", mpr121->keycount);
 		return -EINVAL;