Add basic riscv64 architecture support

[vhaudiquet]

This adds basic riscv64 architecture support.
It allows building the snap on riscv64, and then running basic commands:

ubuntu@p550:~$ inference-snaps-cli show-machine
cpus:
    - architecture: riscv64
      isa:
        - rv64imafdch
        - zicsr
        - zifencei
        - zba
        - zbb
        - sscofpmf
memory:
    total-ram: 16743100416
    total-swap: 0
disk:
    /var/lib/snapd/snaps:
        total: 125930070016
        avail: 14767624192
pci:
    - slot: "0000:00:00.0"
      bus-number: "0x0"
      device-class: "0x604"
      programming-interface: 0
      vendor-id: "0x1FE1"
      device-id: "0x2030"
      vendor-name: Beijing ESWIN Computing Technology Co., Ltd.
      device-name: EIC7700 Root Complex

The CPU detection shows available RISC-V ISA extensions, allowing for future riscv64 vector/matrix engine detection.

We can also run the engine selection code on test data:

ubuntu@p550:~$ inference-snaps-cli show-machine --format=json | inference-snaps-cli debug select-engine --engines test_data/engines/
❌ amd-gpu - not compatible: required device not found
❌ ampere - not compatible: required device not found
❌ ampere-altra - not compatible: required device not found
❌ arm-neon - not compatible: required device not found
✅ cpu - compatible, score = 12
❌ cpu-avx1 - not compatible: required device not found
❌ cpu-avx2 - not compatible: required device not found
❌ cpu-avx512 - not compatible: required device not found
❌ cpu-exptl - not compatible: required device not found
❌ cuda-generic - not compatible: required device not found
❌ example-memory - not compatible: insufficient memory, insufficient disk space, required device not found
❌ intel-cpu - not compatible: required device not found
❌ intel-gpu - not compatible: required device not found
❌ intel-npu - not compatible: required device not found
❌ not-compatible-engine - not compatible: required device not found
❌ rocm-generic - not compatible: required device not found
Selected engine for your hardware configuration: cpu

engines:
    - name: amd-gpu
      description: AMD specific engine targeting only one microarchitecture.
      vendor: Canonical Ltd
...

[farshidtz]

This is a great addition, @vhaudiquet. Would you mind adding this to https://github.com/canonical/lscompute? We've moved the hardware_info package to a separate module and will just be referencing it here. We could merge and migrate it ourselves, but it would be better if it were authored by you directly.

[vhaudiquet]

Sure! That works for me. Should I close this then?

EDIT: Ah, maybe we need to keep the modification to snapcraft.yaml here. I can remove the other modifications and send them to lscompute

[farshidtz]

I suggest focusing on the "lscompute" snap that is on the other side. We can then add anything that's useful to stack-utils. The stack-utils snap is only used for dev testing.

Thank you!