ghash-ia64.pl: excuse myself from implementing "528B" variant.

# something else sha1-ia64.pl module processes one byte in 6.0 cycles.

# On Itanium GHASH should run at ~8.5 cycles per byte.

# Note about "528B" variant. In Itanium 2 case it makes lesser sense

# to implement it for following reason. Because number of functional

# units is naturally limited, it's impossible to implement "528B" loop

# in 4 cycles, only in 5. This means that theoretically performance

# improvement can't be more than 20%, ~15% is more realistic. This

# is considered below justification level for implementing new code.

# Not to mention that on original Itanium it would actually run

# slower, spending >9 cycles per byte.

$output=shift and (open STDOUT,">$output" or die "can't open $output: $!");

if ($^O eq "hpux") {