powerpc/pseries: Update hv-24x7 information after migration

Function 'read_sys_info_pseries()' is added to get system parameter
values like number of sockets and chips per socket.
and it gets these details via rtas_call with token
"PROCESSOR_MODULE_INFO".

Incase lpar migrate from one system to another, system
parameter details like chips per sockets or number of sockets might
change. So, it needs to be re-initialized otherwise, these values
corresponds to previous system values.
This patch adds a call to 'read_sys_info_pseries()' from
'post-mobility_fixup()' to re-init the physsockets and physchips values
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200525104308.9814-6-kjain@linux.ibm.com

arch/powerpc/platforms/pseries/mobility.c

@@ -371,6 +371,9 @@ void post_mobility_fixup(void)
 	/* Possibly switch to a new RFI flush type */
 	pseries_setup_rfi_flush();
 
+	/* Reinitialise system information for hv-24x7 */
+	read_24x7_sys_info();
+
 	return;
 }