distrooverrides: Move back to classes whilst it's usage is clarified

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/classes-recipe/distrooverrides.bbclass b/meta/classes/distrooverrides.bbclass
similarity index 100%
rename from meta/classes-recipe/distrooverrides.bbclass
rename to meta/classes/distrooverrides.bbclass