Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index 480567e..e9c8a60 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -904,7 +904,7 @@
 	printk(KERN_INFO "SMU i2c %s\n", controller->full_name);
 
 	/* Look for childs, note that they might not be of the right
-	 * type as older device trees mix i2c busses and other thigns
+	 * type as older device trees mix i2c busses and other things
 	 * at the same level
 	 */
 	for (busnode = NULL;