MAINTAINERS: Add myself as a reviewer of PowerNV emulation

MAINTAINERS: Add myself as a reviewer of PowerNV emulation

Proposing myself as a reviewer in the PowerNV emulation in QEMU

Have been working on PowerNV QEMU for sometime, with contributions in
Power11, MPIPL and minor fixes and things such as dtb support

Cc: Cédric Le Goater <clg@kaod.org>
Cc: Frédéric Barrat <fbarrat@linux.ibm.com>
Cc: Mahesh J Salgaonkar <mahesh@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250724100623.3071131-5-harshpb@linux.ibm.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>