Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index 9ee4c78..b4488c8 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -649,7 +649,7 @@
 		/* multiple devices could exist */
 		st_kim_devices[pdev->id] = pdev;
 	} else {
-		/* platform's sure about existance of 1 device */
+		/* platform's sure about existence of 1 device */
 		st_kim_devices[0] = pdev;
 	}