Bluetooth: Controller: Fix reschedule for ticker that yield

Fix reschedule for ticker that yield such that reduce the
slot window after intersection to include required
ticks_slot, and we do not take the interval of the
colliding ticker provided every expiry increments the
interval by random amount of ticks. This is the case for
primary channel advertising.

Fixes commit e1cd5ba77f59 ("Bluetooth: Controller: Fix to
reschedule after overlap when yielding").

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>