It is that maybe less modification working on the components is better, so I just modified the platform
code of AES, SHA and so on.
ESP8266 has no real hardware AES, SHA or bignum peripheral, but some method can speed up the process of part
of upper algorithm, so I also added the platform code of AES, SHA, bignum, ARC, MD5.
ESP8266 has no platform of bignum, so users should not enable the bignum hardware at "menuconfig".
1. support "make size", "make size-files", "make size-components" and "make size-symbols"
2. add esp-idf style link file including "esp8266.ld" and "esp8266.project.ld.in"
3. add link advaced generation file to components of esp8266 and spi_flash
