Bluetooth: Move EIR and CoD update functions to a better position

Due to the upcoming addition of a service cache timer the functions to
update the EIR and CoD need to be higher up in mgmt.c in order to avoid
unnecessary forward-declarations. This patch simply moves code around
without any other changes in order to make subsequent patches more
readable.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>