Add support for STEVAL 3DP001V1 (#12894)

Marlin/src/pins/pins.h

@@ -421,6 +421,8 @@
   #include "pins_ARMED.h"             // STM32F4                                    env:ARMED
 #elif MB(RUMBA32)
   #include "pins_RUMBA32.h"           // STM32F4                                    env:RUMBA32
+#elif MB(STEVAL)
+  #include "pins_STEVAL.h"            // STM32F4                                    env:STM32F4
 
 //
 // ARM Cortex M7