configs/qemu: update xtensa linux to 4.9.16

This fixes the following nommu kernel build issue:

  arch/xtensa/kernel/setup.c: In function 'cpu_reset':
  arch/xtensa/kernel/setup.c:553:2: error: implicit declaration of function
    'local_flush_tlb_all' [-Werror=implicit-function-declaration]
    local_flush_tlb_all();

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

configs/qemu_xtensa_lx60_defconfig

@@ -22,7 +22,7 @@ BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_9=y
 # Kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.9.6"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.9.16"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/xtensa-lx60/linux-4.9.config"
 BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM=y

configs/qemu_xtensa_lx60_nommu_defconfig

@@ -26,7 +26,7 @@ BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_9=y
 # Kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.9.6"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.9.16"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/xtensa-lx60/linux-4.9-nommu.config"
 BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM=y