Bluetooth: controller: split: Fix DLE for remote unsupported Coded PHY

Fix Data Length Procedure to use Feature Exchange values to
send correct parameters based on whether Coded PHY is
supported by remote peer.

Relates to BT TS.5.1.1 tests:
LL/CON/MAS/BV-129-C
LL/CON/MAS/BV-130-C
LL/CON/SLA/BV-132-C
LL/CON/SLA/BV-133-C

Relates to commit fca32e41 ("Bluetooth: controller: Fix
DLE for remote unsupported Coded PHY").

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