Added a new feature to CHI protocol (in collaboration with @tiagormk).
Here is the Jira Ticket
[https://gem5.atlassian.net/browse/GEM5-1326](https://gem5.atlassian.net/browse/GEM5-1326
). As described in CHI specs, far atomic transactions enable remote
execution of Atomic Memory Operations. This pull request incorporates
several changes:
* Fix Arm ISA definition of Swap instructions. These instructions should
return an operand, so their ISA definition should be Return Operation.
* Enable AMOs in Ruby Mem Test to verify that AMOs work
* Enable near and far AMO in the Cache Controler of CHI
Three configuration parameters have been used to tune this behavior:
* policy_type: sets the atomic policy to one of the described in [our
paper](https://dl.acm.org/doi/10.1145/3579371.3589065)
* atomic_op_latency: simulates the AMO ALU operation latency
* comp_anr: configures the Atomic No return transaction to split
CompDBIDResp into two different messages DBIDResp and Comp
ae104cc431