Add a non-SSE implementation of the QuickTexHash.

This way we can use it as a stable value for texture replacements.
Attempt to match the SSE2 version of the hash.

Not tested, don't currently have an ARM device.  May or may not have a
performance hit.
Fix reversed consts in hand-neon texhash.
Merge pull request #7029 from unknownbrackets/texhash

Attempt to make the texture hash match(able) - needs testing
Didn't mean to keep this check.