target/i386/kvm: Restrict SEV stubs to x86 architecture

SEV is x86-specific, no need to add its stub to other
architectures. Move the stub file to target/i386/kvm/.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211007161716.453984-5-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

accel/kvm/meson.build

@@ -3,6 +3,5 @@ kvm_ss.add(files(
   'kvm-all.c',
   'kvm-accel-ops.c',
 ))
-kvm_ss.add(when: 'CONFIG_SEV', if_false: files('sev-stub.c'))
 
 specific_ss.add_all(when: 'CONFIG_KVM', if_true: kvm_ss)

target/i386/kvm/meson.build

@@ -7,6 +7,8 @@ i386_softmmu_kvm_ss.add(files(
   'kvm-cpu.c',
 ))
 
+i386_softmmu_kvm_ss.add(when: 'CONFIG_SEV', if_false: files('sev-stub.c'))
+
 i386_softmmu_ss.add(when: 'CONFIG_HYPERV', if_true: files('hyperv.c'), if_false: files('hyperv-stub.c'))
 
 i386_softmmu_ss.add_all(when: 'CONFIG_KVM', if_true: i386_softmmu_kvm_ss)