Documentation: power: Fix typo in Documentation/power

This patch fix spelling typos found in Documentation/power.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --cc Documentation/power/runtime_pm.txt
Simple merge

diff --cc Documentation/power/suspend-and-interrupts.txt
Simple merge

diff --cc Documentation/power/userland-swsusp.txt
Simple merge