MAINTAINERS: Adding myself in the list for ppc/spapr

Would like to get notified of changes in this area and review them.

Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20230503093619.2530487-3-harshpb@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

MAINTAINERS

@@ -1422,6 +1422,7 @@ M: Daniel Henrique Barboza <danielhb413@gmail.com>
 R: Cédric Le Goater <clg@kaod.org>
 R: David Gibson <david@gibson.dropbear.id.au>
 R: Greg Kurz <groug@kaod.org>
+R: Harsh Prateek Bora <harshpb@linux.ibm.com>
 L: qemu-ppc@nongnu.org
 S: Odd Fixes
 F: hw/*/spapr*