Fix infinite recursion in host-based bt_rand function. This would call
HCI LE Random Number command, which would in turn call bt_rand, causing
an infinite recursion.
bt_rand -> prng_reseed -> BT_HCI_OP_LE_RAND -> le_rand -> bt_rand
To solve this issue the controller should avoid doing calls into the
host, so all calls to bt_rand in the controller should be replaced with
a call to a controller function.
Fixes#22202
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>