Add action to enable LTO in Samsung kernels

This action enables Link Time Optimization (LTO) for Samsung kernels.

.github/actions/lto/action.yml

@@ -0,0 +1,11 @@
+name: enable LTO
+description: samsung seems to have no LTO in their kernels, this enables it
+
+runs:
+ using: composite
+ steps:
+  - name: enable FULL LTO
+    shell: bash
+    run: |
+     cd "$COMMON"
+     sed -i '/^default LTO_NONE$/s/default LTO_NONE/default LTO_CLANG_FULL/' arch/Kconfig