Add logging library
Logging library, intended to be used across other components.
Uses design similar to Android NDK logging APIs and allows for both compile time and run time filters, similar to logcat.
Also includes cleanup of cpu_startup.c — i was changing some logging output in this file so decided to re-format it and reduce code duplication.
Ref TW6703
See merge request !68
Move CPU region protection setup into soc/cpu.h
change tabs to spaces
remove unused extern declarations
use RTC_WDTCONFIG0 instead of numeric address (still need to fix BB reg)
Note that with WiFi stack enabled, system_init will reset frequency to 240MHz.
To make this setting useful, esp32-wifi-libs submodule needs to be updated.
1. timer reg file for both time group 0 and time group 1, not only timer group 0
2. fix bug that io mux header file mismatch with chip
3. fix bug that some BASE address not correct
4. add some static function to eagle.fpga32.rom.addr.v7.ld
5. add interrupts usage table
6. add some comments for rom code functions