numa: Move NUMA declarations from sysemu.h to numa.h

Not all sysemu.h users need the NUMA declarations, and keeping them in a
separate file makes it easier to see what are the interfaces provided by
numa.c.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

hw/mem/pc-dimm.c

@@ -22,6 +22,7 @@
 #include "qemu/config-file.h"
 #include "qapi/visitor.h"
 #include "qemu/range.h"
+#include "sysemu/numa.h"
 
 typedef struct pc_dimms_capacity {
      uint64_t size;