crypto: qat - make state machine functions static

The state machine functions adf_dev_init(), adf_dev_start(),
adf_dev_stop() adf_dev_shutdown() and adf_dev_shutdown_cache_cfg()
are only used internally within adf_init.c.
Do not export these functions and make them static as state transitions
are now performed using the safe function adf_dev_up() and
adf_dev_down().

This commit does not implement any functional change.

Signed-off-by: Shashank Gupta <shashank.gupta@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>