Fix typos in Documentation/: 'S'

This patch fixes typos in various Documentation txts. The patch addresses
some words starting with the letter 'S'.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Alan Cox <alan@redhat.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

Documentation/powerpc/booting-without-of.txt

@@ -550,11 +550,11 @@ Here's the basic structure of a single node:
      * [child nodes if any]
      * token OF_DT_END_NODE (that is 0x00000002)
 
-So the node content can be summmarised as a start token, a full path,
-a list of properties, a list of child node and an end token. Every
+So the node content can be summarised as a start token, a full path,
+a list of properties, a list of child nodes, and an end token. Every
 child node is a full node structure itself as defined above.
 
-4) Device tree 'strings" block
+4) Device tree "strings" block
 
 In order to save space, property names, which are generally redundant,
 are stored separately in the "strings" block. This block is simply the