Documentation: leds: Correct spelling

Correct spelling problems for Documentation/leds/ as reported
by codespell.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230127064005.1558-15-rdunlap@infradead.org