include: Fixes #1205, C++ usage of sensor.h
include: Fixes #1205, C++ usage of sensor.h

I ran into issue #1205 earlier today and realized the fix was to simply
provide the proper casts.  The issue is that C++ is less permissive than
C here, erroring when trying to implicitly convert from `void *` to
`struct gpio_driver_api *`.  The same cast is done in
include/drivers/gpio.h, which is why I did that here as well.

This fix was validated by compiling my C++ application successfully and
also successfully running my app on my board, interacting with sensors.

Signed-off-by: Brooks Prumo <36dc6978501422e22f86ddb0b443192ade5edf35@prumo.org>

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