UPSTREAM: Documentation: leds: standartizing LED names

We have a list of valid functions, but LED names in sysfs are still
far from being consistent. Create list of "well known" LED names so we
nudge people towards using same LED names (except color) for same
functionality.

Signed-off-by: Pavel Machek <pavel@ucw.cz>

Bug: 260685629
(cherry picked from commit 09f12730)
Change-Id: Iea12a9c230d6cd072b0f4fd4e0c616348173dd53
Signed-off-by: Farid Chahla <farid.chahla@sony.com>