linux-headers: bump 3.12.x series

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/linux-headers/Config.in.host

@@ -211,7 +211,7 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "3.2.78"	if BR2_KERNEL_HEADERS_3_2
 	default "3.4.110"	if BR2_KERNEL_HEADERS_3_4
 	default "3.10.99"	if BR2_KERNEL_HEADERS_3_10
-	default "3.12.55"	if BR2_KERNEL_HEADERS_3_12
+	default "3.12.56"	if BR2_KERNEL_HEADERS_3_12
 	default "3.14.63"	if BR2_KERNEL_HEADERS_3_14
 	default "3.17.8"	if BR2_KERNEL_HEADERS_3_17
 	default "3.18.28"	if BR2_KERNEL_HEADERS_3_18