PCI: dwc: Set PORT_LINK_DLL_LINK_EN in common setup code

The Intel driver is the only one to set PORT_LINK_DLL_LINK_EN. The
default value is set and it seems pretty certain that enabling link
initialization is always required. Maybe it could just be dropped from
the Intel driver, but lets move setting it into the common code to be
sure.

Link: https://lore.kernel.org/r/20200821035420.380495-36-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Dilip Kota <eswara.kota@linux.intel.com>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>