cxl/pmem: Remove is_cxl_nvdimm_bridge()

Remove is_cxl_nvdimm_bridge() which has no caller now.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-11-6623037414d4@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>