make menuconfig: run kconfig with DISTORTOS_PATH environment variable
make menuconfig: run kconfig with DISTORTOS_PATH environment variable

This way running "make menuconfig" will always run in top project's
folder, even when running this command in distortosTemplateSubfolder
project.
CezaryGapinski/distortos,DISTORTEC/distortos,jasmin-j/distortos,DISTORTEC/distortos,DISTORTEC/distortos,jasmin-j/distortos,DISTORTEC/distortos,CezaryGapinski/distortos,jasmin-j/distortos,CezaryGapinski/distortos,jasmin-j/distortos,jasmin-j/distortos,CezaryGapinski/distortos,CezaryGapinski/distortos