Cleanup and refactoring of the STM32w port

This is a general cleanup of things like code style issues and code structure of the STM32w port to make it more like the rest of Contiki is structured.

cpu/stm32w108/e_stdio/src/test-mes.c

@@ -0,0 +1,44 @@
+
+#define FLOATING
+#define PRINT
+#define SCANF
+
+
+int main() {
+
+char ent_char		;
+float flottant		;
+
+#ifndef FLOATING
+#ifdef PRINT
+ ent_char='a';
+#endif
+
+#ifdef SCANF
+  scanf("%c" , &ent_char);
+#endif
+
+#ifdef PRINT
+  printf("%c\n", ent_char);
+#endif
+
+
+
+#else
+ #ifdef PRINT
+ flottant = 1.456789;
+#endif
+
+#ifdef SCANF
+  scanf("%f" , &flottant);
+#endif
+
+#ifdef PRINT
+  printf("%f\n", flottant);
+#endif
+
+#endif
+  return 0;
+
+ }
+