New kernel drivers and device implementation updates (#561)

- Added modular device support and devicetree bindings for ILI9341, ILI9488, CST816S, XPT2046, and GPIO button input, updating several board configurations for display/touch/backlight/keyboard/battery.
- Added a setting to control deprecated HAL usage (device property + Kconfig).

Firmware/Source/Main.cpp

@@ -9,8 +9,13 @@
 #include <Simulator.h>
 #endif
 
+#ifdef CONFIG_TT_USE_DEPRECATED_HAL
 // Each board project declares this variable
 extern const tt::hal::Configuration hardwareConfiguration;
+#else
+// Legacy placeholder (required until legacy HAL is cleaned up everywhere)
+extern const tt::hal::Configuration hardwareConfiguration = {};
+#endif
 
 extern "C" {