calao_usb_a9260_defconfig: lock to kernel 3.10.x

The calao defconfig fails to build with 3.11, so lock the kernel version
to the last version known to build.

For details, see:
http://jenkins.free-electrons.com/job/buildroot/config=calao_usb_a9260_defconfig/105

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

configs/calao_usb_a9260_defconfig

@@ -10,6 +10,8 @@ BR2_TARGET_AT91BOOTSTRAP_NANDFLASH=y
 BR2_TARGET_BAREBOX=y
 BR2_TARGET_BAREBOX_BOARD_DEFCONFIG="usb_a9260"
 BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="3.10.10"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/calao/usb-a9260/linux-3.7.4.config"
 BR2_LINUX_KERNEL_ZIMAGE=y