PCI: keystone: Add workaround for Errata #i2037 (AM65x SR 1.0)

PCI: keystone: Add workaround for Errata #i2037 (AM65x SR 1.0)

Errata #i2037 in AM65x/DRA80xM Processors Silicon Revision 1.0
(SPRZ452D_July 2018_Revised December 2019 [1]) mentions when an
inbound PCIe TLP spans more than two internal AXI 128-byte bursts,
the bus may corrupt the packet payload and the corrupt data may
cause associated applications or the processor to hang.

The workaround for Errata #i2037 is to limit the maximum read
request size and maximum payload size to 128 bytes. Add workaround
for Errata #i2037 here.

The errata and workaround is applicable only to AM65x SR 1.0 and
later versions of the silicon will have this fixed.

[1] -> https://www.ti.com/lit/er/sprz452i/sprz452i.pdf

Link: https://lore.kernel.org/linux-pci/16e1fcae-1ea7-46be-b157-096e05661b15@siemens.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Achal Verma <a-verma1@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>