Move nonce creation from csprng backend to random main module.
* random/random-csprng.c (_gcry_rngcsprng_create_nonce): Remove. (nonce_buffer_lock): Remove. (initialize_basics): Remove init of nonce_buffer_lock. * random/random.c: Add a few header files. (nonce_buffer_lock): New. (_gcry_random_initialize): Init nonce_buffer_lock. (gcry_create_nonce): Add code from _gcry_rngcsprng_create_nonce. * random/random-daemon.c (_gcry_daemon_create_nonce): Remove.
The nonce generation code is useful for all RNG types and thus it
should be in random.c. The only exception is the fips-mode, which
requires the use of the fips nonce generator.