ks_pcie_link_up() uses registers from the designware core to get the
status of the link. Move the register defines to pcie-designware.h
and cleanup ks_pcie_link_up().
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>