hw/timer: Revert "hpet: inverse polarity when pin above ISA_NUM_IRQS"

This reverts commit 0d63b2dd.

This change was originally intended to correct the HPET behavior
in conjunction with Linux, however the behavior that it actually creates
is not compatible with the ioapic.c implementation; it used to be
compatible with KVM's own IOAPIC but it is not anymore.

Signed-off-by: Bill Paul <wpaul@windriver.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <201604051558.20070.wpaul@windriver.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>