samples: bluetooth: hci_uart: update nrf52840_pca10090 config

Enable the GPIO reset pin feature of nrf52840_pca10090
on pin P1.02 and the wait NOP feature of the controller.
These are used to let nrf9160_pca10090 synchronize the
HCI communication with nrf52840_pca10090 controllers.

Signed-off-by: Emanuele Di Santo <emdi@nordicsemi.no>