PCI: keystone: Prefer of_device_get_match_data()

The keystone driver only needs the device data, not the whole struct
of_device_id.  Use of_device_get_match_data() instead of of_match_device().
No functional change intended.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20211223011054.1227810-7-helgaas@kernel.org


Signed-off-by: Fan Fei <ffclaire1224@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>