apic, i386/tcg: add x2apic transitions

apic, i386/tcg: add x2apic transitions

This commit adds support for x2APIC transitions when writing to
MSR_IA32_APICBASE register and finally adds CPUID_EXT_X2APIC to
TCG_EXT_FEATURES.

The set_base in APICCommonClass now returns an integer to indicate error in
execution. apic_set_base return -1 on invalid APIC state transition,
accelerator can use this to raise appropriate exception.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Message-Id: <20240111154404.5333-4-minhquangbui99@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>