usb: bluetooth: Incrase data stage buffer for setup transfers.

Depending on the Bluetooth features enabled, the HCI
packets can be 264 Bytes long. For HCI over USB the HCI packet
is handled in data stage of USB transfer. Buffer for the data
stage was too short and USB driver was STALLing the data stage
making it unable to complete. Extend the data stage buffer
to 266 Bytes if HCI USB is selected and BT_RX_BUF_LEN > 127
indicating that longer HCI packets are needed.

Signed-off-by: Emil Obalski <emil.obalski@nordicsemi.no>