MAINTAINERS: Update KVM RISC-V entry to cover selftests support

We update KVM RISC-V maintainers entry to include appropriate KVM
selftests directories so that RISC-V related KVM selftests patches
are CC'ed to KVM RISC-V mailing list.

Signed-off-by: Anup Patel <anup@brainfault.org>

Author: avpatel

MAINTAINERS

@@ -10769,6 +10769,8 @@ T:	git git://github.com/kvm-riscv/linux.git
 F:	arch/riscv/include/asm/kvm*
 F:	arch/riscv/include/uapi/asm/kvm*
 F:	arch/riscv/kvm/
+F:	tools/testing/selftests/kvm/*/riscv/
+F:	tools/testing/selftests/kvm/riscv/
 
 KERNEL VIRTUAL MACHINE for s390 (KVM/s390)
 M:	Christian Borntraeger <borntraeger@linux.ibm.com>