arm: a37xx: pci: Implement re-issuing config requests on CRS response

arm: a37xx: pci: Implement re-issuing config requests on CRS response

According to PCIe base specification, if CRS Software Visibility is not
enabled, the Root Complex must re-issue the Configuration Request as a new
Request.

Normally this part of Root Complex is implemented in hardware but aardvark
is somehow special and does not implement it in hardware and expect that
handling of config requests are fully implemented in software.

This re-issuing functionality is required also because U-Boot does not
support CRS Software Visibility feature and therefore expects that Root
Complex re-issues requests as is specified in PCIe base specification.

Retry / re-issue config request up to the PIO_MAX_RETRIES, to prevent
infinite loop. After retry count exceed PIO_MAX_RETRIES, returns failure.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>