llext: remove superfluous symbol exports

[lyakh]

I've checked all the external symbols in currently built LLEXT modules and probe and compared them to all the exported symbols. This commit removes most of needlessly exported symbols, except mathematics functions.

[Copilot]

Pull request overview

This PR removes unnecessary symbol exports (EXPORT_SYMBOL macros) that are not used by LLEXT modules, cleaning up the API surface to only expose what is actually needed.

Changes:

• Removed 32 EXPORT_SYMBOL macros across 8 files for functions that are not used by LLEXT modules
• Removed rtos/symbol.h includes from 3 files that no longer have any symbol exports
• Cleaned up trailing whitespace where EXPORT_SYMBOL macros were removed

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/lib/dma.c	Removed 4 DMA-related symbol exports and the symbol.h include
src/ipc/ipc4/helper.c	Removed 1 audio format conversion symbol export
src/debug/debug_stream/debug_stream_text_msg.c	Removed debug message symbol export
src/audio/module_adapter/module_adapter_ipc4.c	Removed 7 module adapter IPC4 function exports
src/audio/module_adapter/module_adapter.c	Removed 13 module adapter function exports and the symbol.h include
src/audio/module_adapter/module/generic.c	Removed 2 generic module function exports
src/audio/drc/drc_log.c	Removed 3 DRC logging-related symbol exports and the symbol.h include
src/audio/component.c	Removed component registration symbol export

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[lgirdwood]

build test will confirm none are needed.

[lyakh]

build test will confirm none are needed.

@lgirdwood nnno, build doesn't check that. Only run-time. And actually even then mostly only if those functions happen to get called. So, say, if function fff() isn't exported, and a module has a call to it, LLEXT will complain when linking. But if that module doesn't happen to call it, nothing bad would happen. But in fact some time ago we made missing symbols errors, so now yes, runtime will fail. But not build.

[lgirdwood]

build test will confirm none are needed.

@lgirdwood nnno, build doesn't check that. Only run-time. And actually even then mostly only if those functions happen to get called. So, say, if function fff() isn't exported, and a module has a call to it, LLEXT will complain when linking. But if that module doesn't happen to call it, nothing bad would happen. But in fact some time ago we made missing symbols errors, so now yes, runtime will fail. But not build.

ok, but the CI will have full coverage here which is good.

[lyakh]

build test will confirm none are needed.

@lgirdwood nnno, build doesn't check that. Only run-time. And actually even then mostly only if those functions happen to get called. So, say, if function fff() isn't exported, and a module has a call to it, LLEXT will complain when linking. But if that module doesn't happen to call it, nothing bad would happen. But in fact some time ago we made missing symbols errors, so now yes, runtime will fail. But not build.

ok, but the CI will have full coverage here which is good.

@lgirdwood actually also not quite, sorry. We don't test all the LLEXT modules. So if I by chance remove an exported symbol that's needed by another module, that we aren't testing in CI, it won't be caught. But the probability is low and even if we do break something, fixing it would be simple because these errors are printed explicitly in the log when a symbol is missing.