ppc/spapr: Add hotremovable flag on DIMM LMBs on drmem_v2

On reboot, all memory that was previously added using object_add and
device_add is placed in this DIMM area.

The new SPAPR_LMB_FLAGS_HOTREMOVABLE flag helps Linux to put this memory in
the correct memory zone, so no unmovable allocations are made there,
allowing the object to be easily hot-removed by device_del and
object_del.

This new flag was accepted in Power Architecture documentation.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20200511200201.58537-1-leobras.c@gmail.com>
[dwg: Fixed syntax error spotted by Cédric Le Goater]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

include/hw/ppc/spapr.h

@@ -886,6 +886,7 @@ int spapr_rtc_import_offset(SpaprRtcState *rtc, int64_t legacy_offset);
 #define SPAPR_LMB_FLAGS_ASSIGNED 0x00000008
 #define SPAPR_LMB_FLAGS_DRC_INVALID 0x00000020
 #define SPAPR_LMB_FLAGS_RESERVED 0x00000080
+#define SPAPR_LMB_FLAGS_HOTREMOVABLE 0x00000100
 
 void spapr_do_system_reset_on_cpu(CPUState *cs, run_on_cpu_data arg);