arch/xtensa: add crt0 to initialize environment

[anjiahao1]

Summary

add crt0 to initialize environment for xtensa arch

we use crt0 inside of start hook in pr #16154, so xtensa also need add it.

Impact

fix xtensa elf build

Testing

build esp32-devkitc:elf

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR does not fully meet the NuttX requirements. While it provides a summary and mentions testing, it lacks crucial details.

Here's a breakdown of what's missing:

• Summary: While it states WHAT was changed (added crt0), it doesn't explain WHY (what problem did this solve? Was there a bug? Missing functionality?). It also lacks HOW it works (what does this crt0 initialization entail?). Issue references are missing.

• Impact: The impact section is too vague. "fix xtensa elf build" is insufficient. Be specific. Does it fix a build failure? Does it change the output binaries in some way? All the other impact categories (user, build process, hardware, documentation, security, compatibility) need to be addressed, even if the answer is "NO". Explicitly stating "NO" for each category demonstrates that these aspects were considered.

• Testing: While it mentions a target, the information is inadequate. What host OS/compiler was used? Crucially, the "Testing logs before change" and "Testing logs after change" sections are empty. Provide concrete evidence that the change works as intended. Show the build failure before the change and the successful build after. Or, if it's not a build failure, show how the behavior differs before and after the change. What specific tests were run?

In short, the PR needs more detail and evidence to demonstrate the change's validity and impact. It needs to convince a reviewer that the change is necessary, works correctly, and doesn't introduce unintended consequences.

[jerpelea]

please update the title to
arch/xtensa: add crt0 to initialize environment

and add a commit description which describes the change

[anjiahao1]

@jerpelea thanks, i add some description for this change

[tmedicci]

Testing on our internal CI...

[tmedicci]

Testing on our internal CI...

Everything is fine with this PR. It solves #16201 . Thanks, @anjiahao1 !