PCI: dwc: designware: Move register defines to designware header file
No functional change. Move the register defines and other macros from
pcie-designware.c to pcie-designware.h. This is in preparation to split the
pcie-designware.c file into designware core file and host-specific file.
While at that also fix a checkpatch warning.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-By: Joao Pinto <jpinto@synopsys.com>