Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/sound/pci/ad1889.c b/sound/pci/ad1889.c
index 4382d0f..d8f6fd6 100644
--- a/sound/pci/ad1889.c
+++ b/sound/pci/ad1889.c
@@ -29,7 +29,7 @@
  *	PM support
  *	MIDI support
  *	Game Port support
- *	SG DMA support (this will need *alot* of work)
+ *	SG DMA support (this will need *a lot* of work)
  */
 
 #include <linux/init.h>