+Stack Protection, +RTL8723AE wifi card, -kernel debugging, -virtualization

The previous commit has been reverted and turned into four distinct commits. Thanks for hinting me there :)

I propose these changes to the kernel config template debian/arch/amd64/config.amd64-vyos:

* Enabled stack overflow protection (CONFIG_CC_STACKPROTECTOR)
  ==> mitigate unknown overflow bugs in socket / network / other code
* Enabled RTL8723AE wifi drivers (CONFIG_RTL8723AE)
  ==> Add support for the Realtek RTL8723AE wifi cards. These come with the Jetway barebone model JBC373F38-525-B which makes for a good mid-sized router. To make this work, you will need the firmware files as well. Please see my pull request on the linux-firmware repo.
* Disabled kernel debugging (CONFIG_DEBUG_KERNEL), since nobody develops drivers using a production config
  ==> Kernel debugging shall not be needed on production line kernels. Therefore I propose to deactivate this to get rid of overhead, slowdowns and maybe security issues.
* Disabled Virtualization (CONFIG_VIRTUALIZATION), since a router is not ment to be a kvm host
  ==> Since this kernel is ment to run as production line on router boxes, I guess there is no need to support hypervisor functionality. Therefore, I porpose to disable this feature.

Best regards!