mmcsd: move block driver register to probe stage in order to read ext_csd reg

[gneworld]

Summary

mmcsd: move block driver register to probe stage in order to read ext_csd reg

Impact

mmcsd

Testing

cortext M55

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR does not meet the NuttX Requirements.

Missing Information:

• Summary:
  • A clear explanation of why this change is necessary is missing. What problem does moving the block driver registration solve?
  • How does moving the registration to the probe stage enable reading the ext_csd register? Provide a technical explanation.
• Impact:
  • The impact section is far too brief. Address all the bullet points (user impact, build impact, etc.) with "YES" or "NO" and provide details where applicable. Even if there's no impact, state "NO" explicitly for clarity.
• Testing:
  • Insufficient Detail: "cortext M55" is not enough information. Specify:
    • Host OS: (e.g., Linux Ubuntu 20.04)
    • Compiler Version: (e.g., GCC 10.3.0)
    • NuttX Configuration: (e.g., configs/cortex-m55/nsh)
  • Missing Logs: Provide actual testing logs from before and after the change to demonstrate the issue and the fix.

Recommendations:

1. Elaborate on the "Why": Clearly state the problem that this change addresses. Why is reading the ext_csd register important, and why was it not possible before?
2. Explain the Technical Details: Describe the code changes and how they enable reading the ext_csd register.
3. Complete the Impact Section: Carefully consider and address all impact points, even if the answer is "NO".
4. Provide Detailed Testing Information: Include specific host and target details, along with actual testing logs demonstrating the problem and the solution.

[xiaoxiang781216]

@gneworld please fix(https://github.com/apache/nuttx/actions/runs/11084304188/job/30799485530?pr=13705):

mmcsd/mmcsd_sdio.c: In function 'mmcsd_slotinitialize':
Error: mmcsd/mmcsd_sdio.c:4367:47: error: 'devname' undeclared (first use in this function); did you mean 'rename'?
 4367 |   finfo("MMC: %s %" PRIu64 "KB %s %s mode\n", devname,
      |                                               ^~~~~~~