Fix "can not" in Documentation and Kconfig

Randy brought it to my attention that in proper english "can not" should always
be written "cannot". I donot see any reason to argue, even if I mightnot
understand why this rule exists.  This patch fixes "can not" in several
Documentation files as well as three Kconfigs.

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/DMA-mapping.txt b/Documentation/DMA-mapping.txt
index 63392c9..1d8dccf 100644
--- a/Documentation/DMA-mapping.txt
+++ b/Documentation/DMA-mapping.txt
@@ -117,7 +117,7 @@
 device supports.  It returns zero if your card can perform DMA
 properly on the machine given the address mask you provided.
 
-If it returns non-zero, your device can not perform DMA properly on
+If it returns non-zero, your device cannot perform DMA properly on
 this platform, and attempting to do so will result in undefined
 behavior.  You must either use a different mask, or not use DMA.