fix(t-deck): restore CALIBRATE_TOUCH so the touch panel is calibrated

The T-Deck touch panel has been uncalibrated on the MUI build since #7142.

device-ui carries calibration parameters for this board and applies them in
LGFXDriver.h, but the whole block is behind `#ifdef CALIBRATE_TOUCH`. That flag
was active for t-deck-tft until 8ae05f6 ("MUI: defcon tft display size
definitions", #7142) commented it out while adding LGFX_SCREEN_WIDTH and
LGFX_SCREEN_HEIGHT. Neither that PR's description nor its discussion mentions
touch, so the change looks unintended.

Without the flag no calibration is applied at all and the panel runs on raw
LovyanGFX values: a touch lands off by the 320/240 ratio, stretched by about
1.33 on X and compressed by about 0.8 on Y, accurate only near the bottom-left
corner and worse with distance from it. Restoring the line makes touch accurate
across the screen.

CALIBRATE_TOUCH=0 applies the stored parameters; 1 would run interactive
calibration, which does not persist yet.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: merocle

variants/esp32s3/t-deck/platformio.ini

@@ -69,7 +69,7 @@ build_flags =
   -D RADIOLIB_DEBUG_SPI=0
   -D RADIOLIB_DEBUG_PROTOCOL=0
   -D RADIOLIB_SPI_PARANOID=0
-;  -D CALIBRATE_TOUCH=0
+  -D CALIBRATE_TOUCH=0
   -D LGFX_SCREEN_WIDTH=240
   -D LGFX_SCREEN_HEIGHT=320
   -D LGFX_BUFSIZE=153600