cxl/pci: Consolidate wait_for_media() and wait_for_media_ready()

Now that wait_for_media() does nothing supplemental to
wait_for_media_ready() just promote wait_for_media_ready() to a common
helper and drop wait_for_media().

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165291686046.1426646.4390664747934592185.stgit@dwillia2-xfh


Signed-off-by: Dan Williams <dan.j.williams@intel.com>