Fix invalid set of the variable

remove fw_att_control base classes: as long as they are not integrated into fw_att_control_main they are useless

Changed naming of the mixers to get rid of umbiguity as outputs are actually going to be driven by io, not fmu
Implemented automatic lookup for the .aux.mix file if it exists

Conflicts:
	Makefile

GPS driver: Add missing wall clock setup for MTK GPS modules

Adding a new base class to remove a lot of boilerplate code, no
functionality changes