Add Ender 2 test and fix pins

.github/workflows/test-builds.yml

@@ -55,6 +55,7 @@ jobs:
         - rambo
         - sanguino1284p
         - sanguino644p
+        - melzi_optiboot
 
         # STM32F1 (Maple) Environments
 

Marlin/src/pins/sanguino/pins_MELZI_CREALITY.h

@@ -46,11 +46,12 @@
 // LCD / Controller
 //
 #if ANY(MKS_MINI_12864, CR10_STOCKDISPLAY, ENDER2_STOCKDISPLAY)
-  #if ENABLED(CR10_STOCKDISPLAY)
+  #if EITHER(CR10_STOCKDISPLAY, ENDER2_STOCKDISPLAY)
     #define LCD_PINS_RS                       28  // ST9720 CS
     #define LCD_PINS_ENABLE                   17  // ST9720 DAT
     #define LCD_PINS_D4                       30  // ST9720 CLK
-  #elif EITHER(MKS_MINI_12864, ENDER2_STOCKDISPLAY)
+  #endif
+  #if EITHER(MKS_MINI_12864, ENDER2_STOCKDISPLAY)
     #define DOGLCD_CS                         28
     #define DOGLCD_A0                         30
   #endif

buildroot/tests/melzi_optiboot

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+#
+# Build tests for melzi_optiboot
+#
+
+# exit on first failure
+set -e
+
+#
+# Ender 2
+#
+use_example_configs Creality/Ender-2
+exec_test $1 $2 "Ender 2" "$3"
+
+# clean up
+restore_configs