Device migrations, new drivers, cleanup (#567)

* **New Features**
  * Added native display support for ST7796, ILI9341, and ST7789 panels across supported boards.
  * Added FT5x06 and FT6x36 touchscreen support.
  * Generic PWM driver
  * ESP32 PWM driver
  * Generic RGB LED driver
  * RGB PWM LED driver
  * RGB GPIO LED driver
  * Implementation of RGB LED for various boards

* **Improvements**
  * Updated board hardware descriptions to use explicit display/touch/backlight device-tree bindings and disabled deprecated HAL usage.
  * Improved display and touch-driver cleanup to prevent stale resources and improve shutdown reliability.
  * Pinned esp-hosted library to a fixed version
 
* **Deletions**
  * Obsolete placeholder display
  * Legacy ILI9488 support.
  * ESP32-specific LEDC PWM implementation

TactilityKernel/bindings/gpio-backlight.yaml

@@ -0,0 +1,16 @@
+description: >
+  Simple GPIO-driven on/off backlight, for panels whose backlight is a single digital
+  enable pin rather than a PWM-dimmable one. Brightness is treated as boolean: any
+  value greater than 0 turns the backlight on, 0 turns it off.
+
+compatible: "gpio-backlight"
+
+properties:
+  pin:
+    type: phandles
+    required: true
+    description: Backlight enable output pin
+  enabled:
+    type: boolean
+    default: false
+    description: Whether the backlight is turned on by set_brightness_default()