drivers: bluetooth: hci: Use TRNG peripheral for BLE purpose on WB0x

Call entropy APIs to use TRNG peripheral on STM32WB0x devices for BLE
purposes.

Enable RNG node on Nucleo-WB0x boards.

Remove RNG initialization as it's done in the entropy driver.

Signed-off-by: Ali Hozhabri <ali.hozhabri@st.com>