risc-v/espressif: Rename espressif/esp32c6 as esp32c6 risc-v/espressif: Rename espressif/esp32h2 as esp32h2
1. Bring up OS kernel. 2. Add interrupt support. 3. Add system timer support. 4. Add the ESP32-C6 devkit board. 5. Add basic UART support for console. 6. Add clock configuration. 7. Add board reset support.