Merge branch 'feature/tw8798_add_phy_printf_into_libcore' into 'master'

esp32: add phy_printf

1. add phy_printf into libcore
2. update libphy.a which has important optimization for ht40 traffic

See merge request !222
This commit is contained in:
Wu Jian Gang
2016-11-21 09:30:09 +08:00