There are two fixes here:

1) s/result/features - the code needs to be checking 'features' here, not
'result'.  Result is the actual cpuflags; features is the condensed set of
things pixman cares about.  Obviously if MMX = 0x1, (result & MMX) will never
give what we want here since for result the MMX bit is 23.

2) On the AMD Geode processor, which has MMX and MMX extensions, just checking
"AuthenticAMD" is not correct.  We need to check for "Geode by NSC" instead.

Credit for the fixes in this patch goes to:

Marco Gritti <mpg at redhat dot com>
Jordan Crouse <jordan dot crouse at amd dot com>