Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index f5cedec..abc1a63 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -292,7 +292,7 @@
 }
 
 /*
- * Allocate a lot of memory, preferrably max_sz but at least min_sz.  In case
+ * Allocate a lot of memory, preferably max_sz but at least min_sz.  In case
  * there isn't much memory do not exceed 1/16th total lowmem pages.  Also do
  * not exceed a maximum number of segments and try not to make segments much
  * bigger than maximum segment size.