PCI: aardvark: Add support for DEVCAP2, DEVCTL2, LNKCAP2 and LNKCTL2 registers on emulated bridge

PCI aardvark hardware supports access to DEVCAP2, DEVCTL2, LNKCAP2 and
LNKCTL2 configuration registers of PCIe core via PCIE_CORE_PCIEXP_CAP.
Export them via emulated software root bridge.

Link: https://lore.kernel.org/r/20211130172913.9727-4-kabel@kernel.org


Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>