Moved FreeRTOSConfig.h from include/freertos to include/esp_additions/freertos.
Updated FreeRTOS.h file to include FreeRTOSConfig.h without the
freertos/ prefix to match with the upstream file.
Renamed architecture specific FreeRTOSConfig.h files to FreeRTOSConfig_arch.h
Signed-off-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>