i386/cpu: Remove the deprecated cpu model 'Icelake-Client'

i386/cpu: Remove the deprecated cpu model 'Icelake-Client'

Icelake, is the codename for Intel 3rd generation Xeon Scalable server
processors. There isn't ever client variants. This "Icelake-Client" CPU
model was added wrongly and imaginarily.

It has been deprecated since v5.2, now it's time to remove it completely
from code.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1647247859-4947-1-git-send-email-robert.hu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>