entropy: bt_hci: driver added

Adds an entropy driver that uses Bluetooth HCI commands as its source
of randomness. As this method is blocking, the ISR API is not supported.

As this method will range from relatively slow (same core Bluetooth HCI
controller) to extremely slow (UART HCI Bluetooth controller), use the
xoshiro PRNG by default for RNG generation.

Implements #37186

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
6 files changed