Bluetooth: samples: hci_uart: Remove unneeded config options

Remove data length and phy update set to 'n' on board that does not
support these features anyway. BT_CTLR_DATA_LEN_SUPPORTED and
BT_CTLR_PHY_UPDATE_SUPPORTED are both set to 'n'.

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