vfio-ioctls: Remove conditional compilation to x86_64 for mshv feature

[jinankjain]

Summary of the PR

We are planning to add support for ARM64 on cloud hypervisor side. Thus, remove the conditional compilation for target_arch x86_64.

Requirements

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• All added/changed functionality has a corresponding unit/integration
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[jinankjain]

friendly ping for reviews? @sameo @sboeuf @jiangliu

[sboeuf]

LGTM

[rbradford]

Here is the dependency chain that leads to toml_edit being pulled in

toml_edit v0.21.1
└── proc-macro-crate v3.1.0
    └── num_enum_derive v0.7.2 (proc-macro)
        └── num_enum v0.7.2
            └── mshv-bindings v0.1.1 (https://github.com/rust-vmm/mshv?branch=main#a2695a5b)
                ├── mshv-ioctls v0.1.1 (https://github.com/rust-vmm/mshv?branch=main#a2695a5b)
                │   └── vfio-ioctls v0.2.0 (/home/rob/src/rust-vmm/vfio/crates/vfio-ioctls)
                └── vfio-ioctls v0.2.0 (/home/rob/src/rust-vmm/vfio/crates/vfio-ioctls)

Might be worth adjusting the features used in mshv-bindings when depending on num_enum crate (see illicitonion/num_enum#18) or maybe drop that depenency if it's not really required.

[jinankjain]

num_enum was recently pulled in the latest commit of mshv: rust-vmm/mshv@a2695a5. Let me see if we can remove toml_edit as a dependency.

[jinankjain]

I have a PR to fix the problem on MSHV side: rust-vmm/mshv#139

[jinankjain]

I tested with the PR branch, and it seems to have fix the problem. Here is a link to test run: https://buildkite.com/rust-vmm/vfio-ioctls-ci/builds/253#018ebdaf-a57c-470c-ba10-3563d6ef2fc5

[jinankjain]

@rbradford Fix in mshv is merged and the pipeline is green now.