[mythtv] denoise3d + Athlon XP bug

[Jay Merrifield]

Hey, I ran across a weird problem with the denoise function and
AthlonXP. AthlonXP registers as a MMX capable processor, but in the
filter_denoise3d.c function, it has #ifdef i386 which isn't being
triggered for my cpu, but when the NewDenoise3dFilter() function gets
called, it checks the MMX flag, which calls denoiseMMX which is now an
empty function (see line 424, 425) so the denoise filter doesn't work.
A simple solution would be to have the MMX function call teh denoise
function, but a better solution would be to have some athlon specific
optimizations (which I lack the specific knowledge). Any thoughts?

Jay