eeprom: at2x: convert to `_dt_spec`
eeprom: at2x: convert to `_dt_spec`

Convert the at2x eeprom driver to `spi_dt_spec` and `i2c_dt_spec`.
I2C functions are not fully converted due to the non-standard addressing
scheme.

Signed-off-by: Jordan Yates <d74a90e280bbad1cc3646781a4e234b467b60fe1@data61.csiro.au>

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