dts: riscv: it8xxx2: fix default status of UART
dts: riscv: it8xxx2: fix default status of UART

The default status of UART should set disabled.
If UART needs to enable, it will be set in the
dts of board level.

Signed-off-by: Tim Lin <38846f7070d5770410e9ef8b439c72e7b53a72c5@ite.corp-partner.google.com>

galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr