zynq_zc706: linux: bump to xilinx-v2017.3 (based on 4.9)

[Build-tested only]
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/zynq_zc706_defconfig

@@ -2,12 +2,12 @@ BR2_arm=y
 BR2_cortex_a9=y
 BR2_ARM_ENABLE_NEON=y
 BR2_ARM_ENABLE_VFP=y
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_4=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_9=y
 BR2_TARGET_GENERIC_GETTY_PORT="ttyPS0"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_GIT=y
 BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/Xilinx/linux-xlnx.git"
-BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="xilinx-v2016.2"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="xilinx-v2017.3"
 BR2_LINUX_KERNEL_DEFCONFIG="xilinx_zynq"
 BR2_LINUX_KERNEL_UIMAGE=y
 BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x8000"