hw/net/vmxnet3: Remove VMXNET3_COMPAT_FLAG_DISABLE_PCIE definition

hw/net/vmxnet3: Remove VMXNET3_COMPAT_FLAG_DISABLE_PCIE definition

VMXNET3_COMPAT_FLAG_DISABLE_PCIE was only used by the
hw_compat_2_5[] array, via the 'x-disable-pcie=on' property.
We removed all machines using that array, lets remove all the
code around VMXNET3_COMPAT_FLAG_DISABLE_PCIE.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20250512083948.39294-19-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>