docs/misra: add Rule 1.1 and 5.6

Rule 1.1 is uncontroversial and we are already following it.

Rule 5.6 has been deemed a good rule to have by the MISRA C group.
However, we do have a significant amount of violations that will take
time to resolve and might require partial deviations in the form of
in-code comments or MISRA C scanners special configurations (ECLAIR).
For new code, we want this rule to generally apply hence the addition to
docs/misra/rules.rst.

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

docs/misra/rules.rst

@@ -82,6 +82,14 @@ maintainers if you want to suggest a change.
      - Summary
      - Notes
 
+   * - `Rule 1.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_01_01.c>`_
+     - Required
+     - The program shall contain no violations of the standard C syntax
+       and constraints, and shall not exceed the implementation's
+       translation limits
+     - We make use of several compiler extensions as documented by
+       `C-language-toolchain.rst <docs/misra/C-language-toolchain.rst>`_
+
    * - `Rule 1.3 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_01_03.c>`_
      - Required
      - There shall be no occurrence of undefined or critical unspecified
@@ -156,6 +164,11 @@ maintainers if you want to suggest a change.
        headers (xen/include/public/) are allowed to retain longer
        identifiers for backward compatibility.
 
+   * - `Rule 5.6 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_05_06.c>`_
+     - Required
+     - A typedef name shall be a unique identifier
+     -
+
    * - `Rule 6.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_06_01.c>`_
      - Required
      - Bit-fields shall only be declared with an appropriate type