rpi: bump kernel version, we need to get rid of this

target/config/Config.in.kernelversion

@@ -232,7 +232,7 @@ config ADK_TARGET_KERNEL_GIT
 config ADK_TARGET_KERNEL_GIT_VER
 	string "kernel version"
 	depends on ADK_TARGET_KERNEL_VERSION_GIT
-	default "4.9.15-1-v7+" if ADK_TARGET_BOARD_BCM28XX
+	default "4.9.16-1-v7+" if ADK_TARGET_BOARD_BCM28XX
 	default "3.14.79-1+" if ADK_TARGET_SYSTEM_SOLIDRUN_IMX6
 	default "4.4.37-1+" if ADK_TARGET_SYSTEM_BEAGLEBONE_BLACK
 	default "2.6.33" if ADK_TARGET_SYSTEM_KINETIS_K70