typo fix to config.sub,

from https://lists.gnu.org/archive/html/config-patches/2023-01/msg00001.html

config.sub

@@ -1075,7 +1075,7 @@ case $cpu-$vendor in
 	pentium-* | p5-* | k5-* | k6-* | nexgen-* | viac3-*)
 		cpu=i586
 		;;
-	pentiumpro-* | p6-* | 6x86-* | athlon-* | athalon_*-*)
+	pentiumpro-* | p6-* | 6x86-* | athlon-* | athlon_*-*)
 		cpu=i686
 		;;
 	pentiumii-* | pentium2-* | pentiumiii-* | pentium3-*)