crypto: qat - rename and relocate GEN2 config function

Rename qat_crypto_dev_config() in adf_gen2_dev_config() and relocate it
to the newly created file adf_gen2_config.c.
This function is specific to QAT GEN2 devices and will be used also to
configure the compression service.

In addition change the drivers to use the dev_config() in the hardware
data structure (which for GEN2 devices now points to
adf_gen2_dev_config()), for consistency.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Adam Guerin <adam.guerin@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>