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".
Commit ID: 97959e77.
Using submodule instead of source code.
It is brought from esp-idf, and some origin dependent code or configuration of hardware have not been removed.
But it maybe not affect using at the ESP8266 platform.
