kni: fix build with kernel 4.15

kni: fix build with kernel 4.15

build error:
.../dpdk/build/build/lib/librte_eal/linuxapp/kni/igb_main.c:2809:2:
 error: implicit declaration of function ‘setup_timer’;
 did you mean ‘sk_stop_timer’? [-Werror=implicit-function-declaration]
  setup_timer(&adapter->watchdog_timer, &igb_watchdog,
  ^~~~~~~~~~~
  sk_stop_timer
cc1: all warnings being treated as errors

error observed whed CONFIG_RTE_KNI_KMOD_ETHTOOL config option enabled.

Because Linux removed setup_timer macros for kernel version >= 4.15
Linux: 513ae785c63c ("timer: Remove setup_*timer() interface")

Replaced setup_timer with timer_setup for new kernel versions.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>