Extend the documentation for the packing library, covering the intended use
for the recently added APIs. This includes the pack() and unpack() macros,
as well as the pack_fields() and unpack_fields() macros.
Add a note that the packing() API is now deprecated in favor of pack() and
unpack().
For the pack_fields() and unpack_fields() APIs, explain the rationale for
when a driver may want to select this API. Provide an example which shows
how to define the fields and call the pack_fields() and unpack_fields()
macros.
Co-developed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241210-packing-pack-fields-and-ice-implementation-v10-4-ee56a47479ac@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>