hw/intc/arm_gicv3: Introduce CONFIG_ARM_GIC_TCG Kconfig selector

hw/intc/arm_gicv3: Introduce CONFIG_ARM_GIC_TCG Kconfig selector

The TYPE_ARM_GICV3 device is an emulated one.  When using
KVM, it is recommended to use the TYPE_KVM_ARM_GICV3 device
(which uses in-kernel support).

When using --with-devices-FOO, it is possible to build a
binary with a specific set of devices. When this binary is
restricted to KVM accelerator, the TYPE_ARM_GICV3 device is
irrelevant, and it is desirable to remove it from the binary.

Therefore introduce the CONFIG_ARM_GIC_TCG Kconfig selector
which select the files required to have the TYPE_ARM_GICV3
device, but also allowing to de-select this device.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20211115223619.2599282-3-philmd@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>