automation/eclair: update configuration of D4.10

MISRA C Directive 4.10 states that "Precautions shall be taken in order
to prevent the contents of a header file being included more than
once".

Add a SAF tag and update the comment on top of cpufeatures.h.
Add a header inclusion guard to compile.h.
Generate header guards for hypercall-defs.h

Update ECLAIR configuration to:
- extend existing deviation to other comments explicitly saying a file
  is intended for multiple inclusion;
- extend existing deviation to other autogenerated files;
- tag the guidelines as clean.

Update deviations.rst accordingly.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

automation/eclair_analysis/ECLAIR/deviations.ecl

@@ -72,11 +72,14 @@ they are not instances of commented-out code."
 -config=MC3A2.D4.3,reports+={deliberate, "any_area(any_loc(file(arm64_bitops))&&context(name(int_clear_mask16)))"}
 -doc_end
 
--doc_begin="Files that are intended to be included more than once do not need to
-conform to the directive."
+-doc_begin="Files that are intended to be included more than once (and have
+a comment that says this explicitly) do not need to conform to the directive."
 -config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* This file is intended to be included multiple times\\. \\*/$, begin-4))"}
--config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* Generated file, do not edit! \\*/$, begin-3))"}
--config=MC3A2.D4.10,reports+={safe, "all_area(all_loc(file(^xen/include/generated/autoconf.h$)))"}
+-config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* Generated file, do not edit! \\*/$, begin-3...begin-2))"}
+-doc_end
+
+-doc_begin="Autogenerated files that do not need to conform to the directive."
+-config=MC3A2.D4.10,reports+={safe, "all_area(all_loc(file(^xen/include/generated/autoconf\\.h$)))"}
 -doc_end
 
 -doc_begin="Including multiple times a .c file is safe because every function or data item