The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
PCI core. This patch adds the driver support for Meson PCIe controller.

Link: https://lore.kernel.org/linux-pci/20181218224708.GB22610@google.com/Signed-off-by: Yue Wang <yue.wang@amlogic.com>
Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
[lorenzo.pieralisi@arm.com: updated coding/comment style]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>