Bluetooth: host: Fix stuck OOB get local functions SC is not supported

Fix bt_le_oob_get_local and bt_le_ext_adv_oob_get_local stuck forever
waiting for the sc_local_pkey_ready semaphore when SC HCI commands
are not supported in the controller.

By using the le_sc_supported helper function the runtime check of HCI
commands and the feature check of CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY
is combined to be handled int the same way.

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>