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/pwm-backlight.yaml

@@ -0,0 +1,19 @@
+description: >
+  PWM-driven display backlight. Wraps any PWM_TYPE device (e.g. espressif,esp32-pwm-ledc or
+  pwm-generic) and maps the brightness-level-range onto its duty cycle.
+
+compatible: "pwm-backlight"
+
+properties:
+  pwm:
+    type: phandles
+    required: true
+    description: The PWM device driving the backlight
+  brightness-level-range:
+    type: values
+    default: [0, 255]
+    description: Inclusive [min,max] brightness range. The minimum value turns the backlight off.
+  brightness-default:
+    type: int
+    default: 200
+    description: Default brightness level, applied by set_brightness_default(). Should fall within brightness-level-range.