have local stdio.h file to avoid newlib issues

... we should move to -nostdinc at some point :/

firmware/libcommon/source/card_emu.c

@@ -19,6 +19,7 @@
 
 //#define TRACE_LEVEL 6
 
+#include <stdio.h>
 #include <assert.h>
 #include <errno.h>
 #include <string.h>

firmware/libcommon/source/stdio.c

@@ -59,10 +59,11 @@
 //------------------------------------------------------------------------------
 //         Global Variables
 //------------------------------------------------------------------------------
+//
+FILE* const stdin = NULL;
+FILE* const stdout = NULL;
+FILE* const stderr = NULL;
 
-// Required for proper compilation.
-struct _reent r = {0, (FILE *) 0, (FILE *) 1, (FILE *) 0};
-struct _reent *_impure_ptr = &r;
 
 //------------------------------------------------------------------------------
 //         Local Functions