debug-info-defconfig: add debug symbols needed by pahole

[plbossart]

With this we can see the structures

pahole -C 'snd_sof_dev' sound/soc/sof/snd-sof.o
struct snd_sof_dev {
	struct device *            dev;                  /*     0     8 */
	spinlock_t                 ipc_lock;             /*     8    72 */
	/* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */
	spinlock_t                 hw_lock;              /*    80    72 */
	/* --- cacheline 2 boundary (128 bytes) was 24 bytes ago --- */
	bool                       dspless_mode_selected; /*   152     1 */

	/* XXX 7 bytes hole, try to pack */

	struct sof_firmware        basefw;               /*   160    16 */

	/* XXX last struct has 4 bytes of padding */

	struct snd_soc_component_driver plat_drv;        /*   176   384 */
...

[plbossart]

Merge delayed until the Jenkins and CI build servers add 'pahole' as a dependency @fredoh9 @ssavati @marc-hb

[fredoh9]

kernel builders have pahole package now.
Let me test build once before merging this.

[fredoh9]

Internal Linux build index 2114 is the one.

Other than checking on output config file, I was able to see pahole ouput.

Without this PR.

(build output directory) $ pahole -C 'snd_sof_dev' sound/soc/sof/snd-sof.o
libbpf: failed to find '.BTF' ELF section in sound/soc/sof/snd-sof.o
pahole: sound/soc/sof/snd-sof.o: Invalid argument

pahole output is interesting to compare with source structures.

[fredoh9]

After merged, I found a interesting change.
There is extra -dbg package is generated. 220MB vs 26MB.
It is not a problem, but I will double check which package will be chosen by the deploy script.

linux-image-6.10.0-rc4-g7f5c1e85f4fe-dbg_6.10.0-rc4-default-topic-sof-dev_amd64.deb	2024-06-27 17:36	220M	 
linux-image-6.10.0-rc4-g7f5c1e85f4fe_6.10.0-rc4-default-topic-sof-dev_amd64.deb	2024-06-27 17:29	26M

[fredoh9]

deploy script chooses -dbg package. It's first hit by name order

[fredoh9]

Sorry, it is a critical problem. looks '-dbg' package is NOT the kernel package, looks only with debug information? It didn't create booting entry. Non debug package has to be installed to boot.

I need to revert this PR. Sorry about too early merge.

internal jenkins log for deploy test,
job/testflow_new/37420/console