Update the periodic sync sample to use the new delayable work API
for blinking the LED.
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
Add LED blinking while scanning for Periodic Advertising,
and LED ON when Periodic Advertising Sync is established.
Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>