This patch adds a description of how operating modes may be specified.
Signed-off-by: Anand K Mistry <amistry@google.com>
Link: https://lore.kernel.org/r/20200702131350.2.I6131e251d13f60d8c5347bb4faa9dc2364c87848@changeidSigned-off-by: Mark Brown <broonie@kernel.org>