remove old iw/iw-full compatibility check

[a-gave]

This remove a compatibility check that search for iw and if not found select iw-full in prometheus related packages.
The iw package is listed since 18.06 https://openwrt.org/packages/index_owrt18_6/start

Instead this check cause a recursive-dependency error, and make the compiler fails.

tmp/.config-package.in:60497:error: recursive dependency detected!
tmp/.config-package.in:60497:	symbol PACKAGE_profile-calafou-indoor depends on PACKAGE_iw
tmp/.config-package.in:131539:	symbol PACKAGE_iw is selected by PACKAGE_kmod-cfg80211
tmp/.config-package.in:22741:	symbol PACKAGE_kmod-cfg80211 is selected by PACKAGE_kmod-batman-adv
tmp/.config-package.in:16661:	symbol PACKAGE_kmod-batman-adv is selected by PACKAGE_lime-proto-batadv
tmp/.config-package.in:61230:	symbol PACKAGE_lime-proto-batadv is selected by PACKAGE_profile-calafou-indoor
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"