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

In the Linux kernel, the following vulnerability has been resolved: 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