Remove smack config fragments in favour of bbappend configuration in iot-security layer

Close for Dab RC1

Previous patch was abandoned and new patchset was prepared.
For TI: https://gerrit.automotivelinux.org/gerrit/#/c/9131/
For Qualcomm: https://gerrit.automotivelinux.org/gerrit/#/c/9133/

Patchset was submitted to upstream.
So we can close this ticket.
Thank you!

I am sorry that I could not attend the F2F meeting.

I checked behaviors of adding kernel config fragment about kernel recipe.
As a result, I found that there is a difference in behavior each kernel recipes.

Some kernel recipes use "linux-yocto.inc" and these recipe have the function of merging cfg.
But Qualcomm and TI kernel do not use "linux-yocto.inc" and they have own function of merging cfg.
So a kernel such as qcom require to set specific setting, I think.

Qualcomm and TI have similar function in kernel recipe.
And it require to set KERNEL_CONFIG_FRAGMENTS.

See:
meta-qcom/recipes-kernel/linux/linux-linaro-qcom.inc
meta-ti/recipes-kernel/linux/setup-defconfig.inc

Fix patch:
https://gerrit.automotivelinux.org/gerrit/#/c/9127/

Sorry for inconvenience. I still wonder why this doesn't work. If we have time, we may have a look with Jan-Simon tomorrow during the F2F meeting in Karlsruhe.

I bitbaked the latest AGL for db410 today.
Unfortunately, smack config for linux kernel is still disable.

I will commit fix patch when I have time.
Thanks!