i2c: xec: Update driver to use gpio_dt_spec
i2c: xec: Update driver to use gpio_dt_spec

Simplify the implementation by using gpio_dt_spec.  Mostly
gpio_dt_spec is used as a common struct and lets us move
away from DT_INST_GPIO_LABEL.

Signed-off-by: Kumar Gala <383ef5577c6e1178b93f59ec8d0936f76d2a98c4@kernel.org>

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