input: Allow key ghosting filter to be disabled

Some keyboards will not need a key ghosting filter, so make this feature
optional.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/input/tegra-kbc.c b/drivers/input/tegra-kbc.c
index 9a30942..6f1cfd8 100644
--- a/drivers/input/tegra-kbc.c
+++ b/drivers/input/tegra-kbc.c
@@ -325,7 +325,7 @@
 			KBC_REPEAT_RATE_MS);
 
 	/* Decode the keyboard matrix information (16 rows, 8 columns) */
-	if (key_matrix_init(&config.matrix, 16, 8)) {
+	if (key_matrix_init(&config.matrix, 16, 8, 1)) {
 		debug("%s: Could not init key matrix\n", __func__);
 		return -1;
 	}