mtdlog: test cases for mtdlog driver.

[Kaben123]

The tests cover basic read/write operations, ioctl interface, and log/block group management.
These tests help ensure the reliability and correctness of the mtdlog driver.

Note: Please adhere to Contributing Guidelines.

Summary

This pull request adds comprehensive unit tests for the mtdlog driver in NuttX apps, located under testing/drivers/drivertest/. The new test file drivertest_mtd_log.c uses the cmocka framework to verify the functionality of the mtdlog driver, including:

• Basic read and write operations to /dev/mtdlog
• Validation of ioctl interfaces (block info, log info, log count, group count, status)
• Log entry and block group management
• Data integrity checks between written and read data

The corresponding build system files (CMakeLists.txt and Makefile) are updated to include the new test when CONFIG_MTDLOG is enabled.

Impact

• Improves test coverage for the mtdlog driver
• No impact on production code; changes are limited to test sources and build scripts
• No breaking changes or compatibility issues

Testing

• The tests are built and executed with CONFIG_MTDLOG enabled
• All test cases pass on supported hardware and emulation environments
• Example test output:

  [==========] Running 3 test(s).
  [ RUN      ] drivertest_mtdlog_case1
  [       OK ] drivertest_mtdlog_case1
  [ RUN      ] drivertest_mtdlog_case2
  [       OK ] drivertest_mtdlog_case2
  [ RUN      ] drivertest_mtdlog_case3
  [       OK ] drivertest_mtdlog_case3
  [==========] 3 test(s) run.
  [  PASSED  ] 3 test(s).
  

[Kaben123]

No need to commit to upstream yet.