T-Echo: use GxEPD2_154_D67 e-ink driver

T-Echo used the fallback GxEPD2_150_BN; on my unit every refresh hit the
10 s busy timeout. Switch to GxEPD2_154_D67 like Meshtastic.

variants/lilygo_techo/platformio.ini

@@ -32,6 +32,11 @@ build_flags = ${nrf52_base.build_flags}
   -D PIN_GPS_RESET_ACTIVE=LOW
   -D TELEM_BME280_ADDRESS=0x77
   -D DISPLAY_CLASS=GxEPDDisplay
+  -D EINK_DISPLAY_MODEL=GxEPD2_154_D67
+  -D EINK_SCALE_X=1.5625f
+  -D EINK_SCALE_Y=1.5625f
+  -D EINK_X_OFFSET=0
+  -D EINK_Y_OFFSET=10
   -D EINK_SCREENOFF_BLANK
   -D UI_RECENT_LIST_SIZE=9
   -D UI_MSG_PREVIEW_SIZE=165

variants/lilygo_techo/variant.h

@@ -131,6 +131,12 @@ extern const int SCK;
 #define DISP_BUSY               (3)
 #define DISP_BACKLIGHT          (43)
 
+// used by GxEPDDisplay when EINK_DISPLAY_MODEL is set
+#define PIN_DISPLAY_CS          DISP_CS
+#define PIN_DISPLAY_DC          DISP_DC
+#define PIN_DISPLAY_RST         DISP_RST
+#define PIN_DISPLAY_BUSY        DISP_BUSY
+
 ////////////////////////////////////////////////////////////////////////////////
 // GPS