Modify the Kconfig name of the mtdconfig module

[zhaoxingyu12]

Note: Please adhere to Contributing Guidelines.

Summary

Modify the Kconfig name of the mtdconfig module

1. MTD_CONFIG_FAIL_SAFE has been renamed to MTD_CONFIG_NVS, and the Kconfig configuration for MTD_CONFIG submodules has been optimized.
   If MTD_CONFIG is enabled, mtd_config.c will be used;
   if MTD_CONFIG_NVS is enabled, mtd_config_nvs.c will be used;
   if neither is enabled, setting MTD_CONFIG_NONE=y.
   These changes are made to facilitate the integration of other mtd_config submodules.

2. All mtd_config submodules should add the mtdconfig_register_by_path and mtdconfig_unregister_by_path APIs. The new mtdconfig_register_by_path and mtdconfig_unregister_by_path APIs allow dynamic registration and unregistration of mtdconfig devices by device path, improving the flexibility of device management.

3. The device dependencies have been adjusted: if MTD_CONFIG is required, it now needs to be set with ifndef CONFIG_MTD_CONFIG_NONE, etc.

Impact

These changes significantly improve the usability and maintainability of the mtdconfig subsystem. By supporting device registration and unregistration by path, developers can manage devices more dynamically and flexibly, adapting to a wider range of application scenarios.
The improvements to the Kconfig options make the configuration interface more user-friendly and the dependencies more intuitive, which is helpful for future feature expansion and maintenance. Overall, these patches enhance the flexibility, reliability, and user experience of mtdconfig.

Testing

test it by CICT together with apache/nuttx-apps#3371

I have conducted tests with CFGDATA on QEMU, and the test results are in line with expectations.

enabled these configurations.
CONFIG_MTD_CONFIG_NVS=y
CONFIG_SYSTEM_CFGDATA=y
CONFIG_MTD_CONFIG_NAMED=y

register lomtdconfig
dd if=/dev/zero of=/data/nvs.img bs=8192 count=10
lomtd -c 2 /dev/config /data/nvs.img

test pass
goldfish-armv7a-ap> cfgdata print mykey
Error reading config entry 'mykey'
goldfish-armv7a-ap> cfgdata set mykey "myvalue"
goldfish-armv7a-ap>
goldfish-armv7a-ap> cfgdata print mykey
myvalue
goldfish-armv7a-ap> cfgdata all
Name Len Data
mykey 8 myvalue

[zhaoxingyu12]

====================================================================================
Configuration/Tool: esp32c3-legacy-devkit/nvcfgdata
2026-01-23 03:19:45

Cleaning...
Configuring...
Building NuttX...
[1/1] Normalize esp32c3-legacy-devkit/nvcfgdata
46d45
< CONFIG_SYSTEM_CFGDATA=y
48d46
< CONFIG_TESTING_MTD_CONFIG_FAIL_SAFE=y
Saving the new configuration file
HEAD detached at pull/18120/merge
Changes not staged for commit:
(use "git add ..." to update what will be committed)
(use "git restore ..." to discard changes in working directory)
modified: boards/risc-v/esp32c3-legacy/esp32c3-legacy-devkit/configs/nvcfgdata/defconfig

no changes added to commit (use "git add" and/or "git commit -a")

report this error, because it needs CICT together with apache/nuttx-apps#3371
in nuttx-apps， it's config has changed to the following depends on, and MTD_CONFIG_NVS enabled @xiaoxiang781216
config SYSTEM_CFGDATA
tristate "Cfgdata Command"
default n
depends on !MTD_CONFIG_NONE

config TESTING_MTD_CONFIG_FAIL_SAFE
tristate "MTD Config fail-safe storage test"
default n
depends on MTD_CONFIG_NVS