LARGE_CONFIG_GET is mainly used to retrieve requested module parameters
but it may also carry TX payload with them. Update its implementation to
account for both TX and RX data.
First reply.header carries total payload size within data_off_sizefield.
Make use of reply.header to realloc returned buffer with correct size.

Failure of IPC request is permissive - error-payload may be returned, an
informative data why GET for given param failed - and thus function
should not collapse before entire processing is finished. Caller is
responsible for checking returned payload and bytes parameters.
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20190808181549.12521-3-cezary.rojewski@intel.comReviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>