hw/intc/riscv_aplic: rename is_kvm_aia()

hw/intc/riscv_aplic: rename is_kvm_aia()

The helper is_kvm_aia() is checking not only for AIA, but for
aplic-imsic (i.e. "aia=aplic-imsic" in 'virt' RISC-V machine) with an
in-kernel chip present.

Rename it to be a bit clear what the helper is doing since we'll add
more AIA helpers in the next patches.

Make the helper public because the 'virt' machine will use it as well.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241119191706.718860-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>