dts: espi: Add dts bindings for eSPI
dts: espi: Add dts bindings for eSPI

Add generic device tree bindings for eSPI devices

Signed-off-by: Jose Alberto Meza <93346bcba00086196ffe58e37d7adff1143c3f07@intel.com>

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