samples: subsys: display: add stm32f469_disco conf file

Add stm32f749i_disco conf file to enable input driver
for touchscreen in LVGL samples applications.

Signed-off-by: Philippe Peurichard <p.peurichard@gmail.com>
diff --git a/samples/subsys/display/lvgl/boards/stm32f469i_disco.conf b/samples/subsys/display/lvgl/boards/stm32f469i_disco.conf
new file mode 100644
index 0000000..c93c2ef
--- /dev/null
+++ b/samples/subsys/display/lvgl/boards/stm32f469i_disco.conf
@@ -0,0 +1,5 @@
+# Copyright (c) Philippe Peurichard <p.peurichard@gmail.com>
+# SPDX-License-Identifier: Apache-2.0
+
+# Enable Input driver for touch screen
+CONFIG_INPUT=y