target/riscv/kvm.c: remove group setting of KVM AIA if the machine only has 1 socket

target/riscv/kvm.c: remove group setting of KVM AIA if the machine only has 1 socket

The emulated AIA within the Linux kernel restores the HART index
of the IMSICs according to the configured AIA settings. During
this process, the group setting is used only when the machine
partitions harts into groups. It's unnecessary to set the group
configuration if the machine has only one socket, as its address
space might not contain the group shift.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231218090543.22353-2-yongxuan.wang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>