Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/video/gbefb.c b/drivers/video/gbefb.c
index 933899d..7e7b7a9 100644
--- a/drivers/video/gbefb.c
+++ b/drivers/video/gbefb.c
@@ -721,7 +721,7 @@
 
 	   Tiles have the advantage that they can be allocated individually in
 	   memory. However, this mapping is not linear at all, which is not
-	   really convienient. In order to support linear addressing, the GBE
+	   really convenient. In order to support linear addressing, the GBE
 	   DMA hardware is fooled into thinking the screen is only one tile
 	   large and but has a greater height, so that the DMA transfer covers
 	   the same region.