check if the config option CONFIG_LANTIQ is defined.
This fixes the following warning:
CC [M] drivers/misc/owl-loader.o
drivers/misc/owl-loader.c: In function 'ath9k_pci_fixup':
drivers/misc/owl-loader.c:92:5: warning: "CONFIG_LANTIQ" is not defined [-Wundef]
#if CONFIG_LANTIQ
^
Fixes: e9401a2335 ("kernel: owl-loader for delayed Atheros ath9k fixup")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>