bpf/Makefile: Introduce coccicheck to run all cocci patches
bpf/Makefile: Introduce coccicheck to run all cocci patches

This commit introduces a new coccicheck target to be able to run all
Coccinelle patches independently from other checks (e.g., sparse).

That target doesn't apply the patch or even display the diff, but it will
print a message for each required change. If the cocci patch supports
adding the required changes automatically, it will also print a final
message with the command to apply all changes.

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,cilium-team/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,cilium-team/cilium,tklauser/cilium,tgraf/cilium