hecl/FourCC: Implement operator!= in terms of operator==
hecl/FourCC: Implement operator!= in terms of operator==

Deduplicates the amount of written code. Now code only needs to ever
change in operator== to automatically reflect across the two functions.

RetroView/hecl,RetroView/hecl,RetroView/hecl,RetroView/hecl