Now that PCI Bridge (PCIe Root Port) for Aardvark is emulated in U-Boot,
add support for handling and propagation of CRSSVE bit.

When CRSSVE bit is unset (default), driver has to reissue config
read/write request on CRS response.

CRSSVE bit is supported only when CRSVIS bit is provided in read-only
Root Capabilities register. So manually inject this CRSVIS bit into read
response for that register.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>