hw/acpi-build: Add a check for memory-less NUMA nodes

Currently, Qemu ACPI builder doesn't consider the memory-less NUMA nodes, eg:

  -m 4G,slots=4,maxmem=8G \
  -numa node,nodeid=0 \
  -numa node,nodeid=1,mem=2G \
  -numa node,nodeid=2,mem=2G \
  -numa node,nodeid=3\

Guest Linux will report

  [    0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0xffffffffffffffff]
  [    0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x00000000-0x0009ffff]
  [    0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x00100000-0x7fffffff]
  [    0.000000] ACPI: SRAT: Node 2 PXM 2 [mem 0x80000000-0xbfffffff]
  [    0.000000] ACPI: SRAT: Node 2 PXM 2 [mem 0x100000000-0x13fffffff]
  [    0.000000] ACPI: SRAT: Node 3 PXM 3 [mem 0x140000000-0x13fffffff]
  [    0.000000] ACPI: SRAT: Node 3 PXM 3 [mem 0x140000000-0x33fffffff] hotplug

[mem 0x00000000-0xffffffffffffffff] and [mem 0x140000000-0x13fffffff] are bogus.

Add a check to avoid building srat memory for memory-less NUMA nodes, also update
the test file. Now the info in guest linux will be

  [    0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x00000000-0x0009ffff]
  [    0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x00100000-0x7fffffff]
  [    0.000000] ACPI: SRAT: Node 2 PXM 2 [mem 0x80000000-0xbfffffff]
  [    0.000000] ACPI: SRAT: Node 2 PXM 2 [mem 0x100000000-0x13fffffff]
  [    0.000000] ACPI: SRAT: Node 3 PXM 3 [mem 0x140000000-0x33fffffff] hotplug

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>