drivers: misc: ti-st: Fix a typo ("unknow")

Spell it as "unknown".

Signed-off-by: Jonathan Neuschäfer <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/ti-st/st_core.c

···
 			ptr++;
 			count--;
 			continue;
-			/* Unknow packet? */
+			/* Unknown packet? */
 		default:
 			type = *ptr;