Fix typos in Documentation/: 'N'-'P'

This patch fixes typos in various Documentation txts. The patch addresses
some words starting with the letters 'N'-'P'.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt
index d859faa..2b35849 100644
--- a/Documentation/power/video.txt
+++ b/Documentation/power/video.txt
@@ -16,7 +16,7 @@
 that.
 
 We either have to run video BIOS during early resume, or interpret it
-using vbetool later, or maybe nothing is neccessary on particular
+using vbetool later, or maybe nothing is necessary on particular
 system because video state is preserved. Unfortunately different
 methods work on different systems, and no known method suits all of
 them.