PCI: keystone: Merge pci-keystone-dw.c and pci-keystone.c

No functional change. Having two different files for keystone PCI driver
doesn't serve any purpose. Merge pci-keystone-dw.c and pci-keystone.c
into a single pci-keystone.c file and remove pci-keystone.h.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/dwc/Makefile

@@ -7,7 +7,7 @@ obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
 obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
-obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
+obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone.o
 obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
 obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
 obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o