find( 
 {wanted=> \&wanted, 
  preprocess => \&preprocess }, #Added this line thats it
 '.');

#Added this function as well
sub preprocess
{
my %afiletimes;
foreach(@_)
{
  $afiletimes{$_} = -M $_ if -f ;
}
@_ = sort { $afiletimes{$b} <=> $afiletimes{$a} } keys %afiletimes;
}