fix typo in kernel headers

toolchain/kernel-headers/Config.in

@@ -130,6 +130,6 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "2.6.22.1"	if BR2_KERNEL_HEADERS_2_6_22_1
 	default "2.6.22.10"	if BR2_KERNEL_HEADERS_2_6_22_10
 	default "2.6.22.10"	if BR2_KERNEL_HEADERS_2_6_22
-	default "2.6.23"	if BR2_KERNEL_HEADERS_2_6_22
+	default "2.6.23"	if BR2_KERNEL_HEADERS_2_6_23
 	default "2.6"		if BR2_KERNEL_HEADERS_SNAP