Fix missing equal sign (#4294)

I just noticed there is a missing equal sign. This PR fixes this.

src/platforms/rcore_drm.c

@@ -206,7 +206,7 @@ static const short linuxToRaylibMap[KEYMAP_SIZE] = {
     [BTN_TL] = GAMEPAD_BUTTON_LEFT_TRIGGER_1,
     [BTN_TL2] = GAMEPAD_BUTTON_LEFT_TRIGGER_2,
     [BTN_TR] = GAMEPAD_BUTTON_RIGHT_TRIGGER_1,
-    [BTN_TR2] GAMEPAD_BUTTON_RIGHT_TRIGGER_2,
+    [BTN_TR2] o">= GAMEPAD_BUTTON_RIGHT_TRIGGER_2,
     [BTN_SELECT] = GAMEPAD_BUTTON_MIDDLE_LEFT,
     [BTN_MODE] = GAMEPAD_BUTTON_MIDDLE,
     [BTN_START] = GAMEPAD_BUTTON_MIDDLE_RIGHT,