arm: virt-acpi: each MADT.GICC entry as enabled unconditionally

in current impl. condition

build_madt() {
  ...
  if (test_bit(i, cpuinfo->found_cpus))

is always true since loop handles only present CPUs
in range [0..smp_cpus).
But to fill usless cpuinfo->found_cpus we do unnecessary
scan over QOM tree to find the same CPUs.
So mark GICC as present always and drop not needed
code that fills cpuinfo->found_cpus.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>
Message-id: 1454323689-248759-1-git-send-email-imammedo@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
