Fix typos in Documentation/: 'F'-'G'

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

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/fb/sisfb.txt b/Documentation/fb/sisfb.txt
index 3b50c51..2e68e50 100644
--- a/Documentation/fb/sisfb.txt
+++ b/Documentation/fb/sisfb.txt
@@ -72,7 +72,7 @@
 supported options including some explanation.
 
 The desired display mode can be specified using the keyword "mode" with
-a parameter in one of the follwing formats:
+a parameter in one of the following formats:
   - XxYxDepth or
   - XxY-Depth or
   - XxY-Depth@Rate or