package/cukinia: fix dependency on gawk

package/cukinia: fix dependency on gawk

gawk can't be selected when busybox is not available as gawk needs
wchar:

WARNING: unmet direct dependencies detected for BR2_PACKAGE_GAWK
  Depends on [n]: BR2_USE_WCHAR [=n] && BR2_USE_MMU [=y] && BR2_PACKAGE_BUSYBOX_SHOW_OTHERS [=y]
  Selected by [y]:
  - BR2_PACKAGE_CUKINIA [=y] && !BR2_PACKAGE_BUSYBOX [=n]

So replace this "select" by a "depends on", as already done by
BR2_PACKAGE_APPARMOR_UTILS_EXTRA

Fixes:
 - http://autobuild.buildroot.org/results/66dacfe7b0783c7df29052fff20f3e79ecbcf054

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>