sim: Align LLVM target info across CMake and Makefile

[no1wudi]

Summary

• Unified the specification of LLVM architecture and ABI types across the CMake and Makefile configurations.
• Introduced LLVM_ARCHTYPE and LLVM_CPUTYPE variables in the CMake configuration to match the Makefile's approach.
• Standardized the ABI type (LLVM_ABITYPE) to sysv for both Linux and macOS host configurations.

Impact

• Ensures consistent LLVM target definitions across build systems (CMake and Makefile).
• Simplifies future maintenance by avoiding divergence in LLVM-related configurations.
• No functional changes to the build output; only the internal representation of LLVM target information is aligned.

Testing

GitHub CI and local build

[nuttxpr]

[Experimental Bot, please feedback here]

Yes, this PR appears to meet the NuttX requirements, although some sections could be more detailed.

Strengths:

• The summary clearly explains the why, what, and how of the changes.
• The impact section addresses most of the required points, highlighting the lack of user-facing changes.
• Reference to GitHub CI and local builds demonstrates testing effort.

Areas for improvement:

• Testing: While mentioning CI and local builds is good, providing specific details is crucial. List the specific build hosts (OS, CPU, compiler) and targets (arch, board, config) used for testing. Include snippets of relevant log output demonstrating the change's effect. The current "Testing logs before/after change" sections are empty.
• Impact - Build: While the impact states "no functional changes," explicitly stating "NO" for "Impact on build" would be clearer. If there are any nuances to the build process change (even if internal), briefly mention them.
• Impact - Other: Consider explicitly stating "NO" for hardware, documentation, security, and compatibility impact if there are truly none. This removes ambiguity. "Anything else to consider?" is also unanswered.
• Issues/PRs: If this PR addresses a specific issue in either the NuttX or NuttX Apps repositories, provide the link.

By adding these specifics, the PR will be more comprehensive and easier for reviewers to assess.