cc3200: Get bootloader compiling with latest overhaul of printf code.

cc3200/bootmgr/bootloader.mk

@@ -60,8 +60,7 @@ BOOT_MAIN_SRC_S = \
 	bootmgr/runapp.s
 
 BOOT_PY_SRC_C = $(addprefix py/,\
-	pfenv.c \
-	pfenv_printf.c \
+	mpprint.c \
 	)
 
 BOOT_STM_SRC_C = $(addprefix stmhal/,\

cc3200/bootmgr/main.c

@@ -347,3 +347,12 @@ int main (void) {
     }
 }
 
+//*****************************************************************************
+//! The following stub function is needed to link mp_vprintf
+//*****************************************************************************
+#include "py/qstr.h"
+
+const byte *qstr_data(qstr q, mp_uint_t *len) {
+    *len = 0;
+    return NULL;
+}