Fix : Multiple advertising feature was not working

Fix : Multiple advertising feature was not working

[Problem] Multiple advertising feature was not working
[Cause & Measure] Advertising slot was not initialized because BT
 chipset supported slot count is over the defined maximum. Platform can
 support the large number of slots if BT chipset can. So we don't need
 to define maximum value of slots. This patch removes the maximum value
 of slots.
[Checking Method] Turn on Bluetooth and check advertising slot's
 initialization.

bt-service-event-receiver.c: __bt_adapter_property_changed_event(847) > name = adv_inst_max
bt-service-event-receiver.c: __bt_adapter_property_changed_event(849) > Value = 17
bt-service-adapter-le.c: _bt_update_le_feature_support(134) > (slot_num > BT_ADV_MULTI_MAX) return
bt-service-event-receiver.c: __bt_adapter_property_changed_event(851) > Fail to update LE feature info

Change-Id: I93e020908636627c9cf0b6ac1377e71126717dd0
Signed-off-by: Seungyoun Ju <sy39.ju@samsung.com>