Update filename and add custom variant.

Variant is based on this PR espressif/arduino-esp32#9386

Author: deisterhold

boards/esp32-s3-touch-lcd-1.28.json renamed to boards/waveshare_esp32s3-touch-lcd-128.json

@@ -6,7 +6,7 @@
     },
     "core": "esp32",
     "extra_flags": [
-      "-DARDUINO_ESP32_S3_TOUCH_LCD_128",
+      "-DARDUINO_WAVESHARE_ESP32S3_TOUCH_LCD_128",
       "-DARDUINO_RUNNING_CORE=1",
       "-DARDUINO_EVENT_RUNNING_CORE=1",
       "-DBOARD_HAS_PSRAM"
@@ -21,7 +21,7 @@
       ]
     ],
     "mcu": "esp32s3",
-    "variant": "esp32s3"
+    "variant": "waveshare_esp32s3_touch_lcd_128"
   },
   "connectivity": [
     "bluetooth",