mac80211: change default SSID from Lede to LEDE

LEDE project seems to be using "LEDE" as its acronym everywhere. To keep
things consistent adjust default wireless SSID.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Jo-Philipp Wich <jo@mein.io>
Acked-by: John Crispin <john@phrozen.org>
Acked-by: Alexander Couzens <lynxis@fe80.eu>