MAINTAINERS: wifi: remove generic wiki links from drivers

The top level entry for wireless drivers already contains to the wiki so no
need to duplicate that in driver entries:

NETWORKING DRIVERS (WIRELESS)
[...]
W:	https://wireless.wiki.kernel.org/



Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230828123603.87621-1-kvalo@kernel.org