Bluetooth: controller: Extend HCI TX cmd buf size for CTE rx param cmd

LE Set Connection CTE Receive Parameters HCI command size may not fit
into HCI TX command buffer size, which default value is 65 bytes.
For platforms other than Nordic there may be up to 75 antenna IDs
put into the command.
Added new default value for SOCs not compatible with Nordic to
extend default TX buf size to 83 bytes (75 bytes for antena IDs,
5 bytes for other command parameters, 3 bytes for command header).

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>