PCI: mvebu: Properly initialize vendor, device and revision of emulated bridge

With this change also PCI vendor id is read from mvebu registers.

Link: https://lore.kernel.org/r/20220104153529.31647-9-pali@kernel.org


Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>