mx6ulpico: Use kernel 4.8-rc5

With kernel 4.8-rc5 we no longer need to use the "CONFIG_SMP=n" workaround
as the reboot issue has been fixed upstream by commit 059e232089e4
("irqchip/gic: Allow self-SGIs for SMP on UP configurations")

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/technexion/imx6ulpico/linux.fragment

@@ -1,2 +1 @@
 CONFIG_CFG80211_WEXT=y
-CONFIG_SMP=n

configs/imx6ulpico_defconfig

@@ -2,8 +2,8 @@
 BR2_arm=y
 BR2_cortex_a7=y
 
-# Linux headers same as kernel, a 4.7 series
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_7=y
+# Linux headers same as kernel, a 4.8 series
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_8=y
 
 # system
 BR2_TARGET_GENERIC_GETTY_PORT="ttymxc5"
@@ -17,7 +17,7 @@ BR2_GLOBAL_PATCH_DIR="board/technexion/imx6ulpico/patches"
 # kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.7"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.8-rc5"
 BR2_LINUX_KERNEL_DEFCONFIG="imx_v6_v7"
 BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/technexion/imx6ulpico/linux.fragment"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y