devices: `sensors` and `libsensors` have hard dependency on `libzynq7000-gpio-msg`

[nalajcie]

• the generic library should depend on common interfaces only, the compiled lib (implementation) should be used implicitly
• as sensors are (surprisingly) a DEFAULT_COMPONENT on imx6ull target subfamily, the libzynq7000-gpio-msg is being compiled there :rofl:
• more robust interface for including available sensors should be designed at a later time