Makefile: Fix make clean because of moving source files.
Makefile: Fix make clean because of moving source files.

silverfilain/L-SMASH,canbal/l-smash,maki-rxrz/L-SMASH,canbal/l-smash,l-smash/l-smash,dwbuiten/l-smash,dwbuiten/l-smash,silverfilain/L-SMASH,mstorsjo/l-smash,maki-rxrz/L-SMASH,l-smash/l-smash,l-smash/l-smash,silverfilain/L-SMASH,mstorsjo/l-smash