OFMatrix4x4: Remove SSE4.1 due to Clang bugs

Clang fails to correctly align the _values ivar in 32 bit mode, despite
OF_ALIGN(16). Trying to force it to align it properly by creating a new
typedef or putting it into an aligned struct instead makes Clang's
builtin memcpy fail in another, entirely unrelated method (that has no
inline assembly), as the inlined memcpy will then try to use movaps on
unaligned data, probably because Clang still assumes the data to be
unaligned there and tries to memcpy using SSE after adding an offset
that would make it aligned - but now makes it unaligned.