linux: Disable debug info

Kernel modules are otherwise huge, which causes problems in particular
for the PAYG UKI.

A better solution would be to build and then split out the debug info.
There are a couple of ways to do this, see:
<#176>

Fixes #178
by bringing the UKI down to a mere 98.6MB.

Author: ssssam

elements/components/linux.bst

@@ -53,6 +53,9 @@ config:
   - |
     python3 debian/scripts/misc/annotations --export --arch "%{debian_arch}" --flavour generic > .config
 
+  - |
+    scripts/config -e DEBUG_INFO_NONE
+
   - |
     make -j1 olddefconfig