Fix includes in esp_err_to_name.c.in.

esp_err_t provided by esp_err.h and thus is required and not optional.
While the python script adds the header, it wraps it with an __has_include
directive that is not supported on all compilers (notably GCC 4.8).

Closes https://github.com/espressif/esp-idf/pull/3424

components/esp_common/src/esp_err_to_name.c

@@ -1,6 +1,7 @@
 //Do not edit this file because it is autogenerated by gen_esp_err_to_name.py
 
 #include <string.h>
+#include "esp_err.h"
 #if __has_include("soc/soc.h")
 #include "soc/soc.h"
 #endif

components/esp_common/src/esp_err_to_name.c.in

@@ -1,6 +1,7 @@
 @COMMENT@
 
 #include <string.h>
+#include "esp_err.h"
 #if __has_include("soc/soc.h")
 #include "soc/soc.h"
 #endif