pftop impossible options in web gui
diag_pftop.php should not have sort options choices of Peak
and Rate since only useful
if have cached information as available
in interactive mode (see text console version)
to calculate the instantaneous speed and peak speed.
Do not offer the 'peak' and 'rate' views for pftop since they only work in interactive mode with cached data, not batch mode like the GUI uses. Fixes #7580