x86/Documentation: Indent 'note::' directive for protocol version number note

The protocol version number note is between the protocol version table and
the memory layout section. As such, Sphinx renders the note directive not
only on the actual note, but until the end of doc.

Indent the directive so that only the actual protocol version number
note is rendered as such.

Fixes: 2c33c27f ("x86/boot: Introduce kernel_info")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231106101206.76487-2-bagasdotme@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/arch/x86/boot.rst

@@ -77,7 +77,7 @@ Protocol 2.14	BURNT BY INCORRECT COMMIT
 Protocol 2.15	(Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.
 =============	============================================================
 
-.. note::
+  .. note::
      The protocol version number should be changed only if the setup header
      is changed. There is no need to update the version number if boot_params
      or kernel_info are changed. Additionally, it is recommended to use