ASoC: Intel: bxtn: Remove code loader reference in cleanup

Since Broxton does not use code loader DMA, remove code loader cleanup
in its dsp cleanup routine. Remove the iounmap too as it is done in
skl_free_dsp().

Signed-off-by: Dronamraju Santosh P K <santosh.pavan.kumarx.dronamraju@intel.com>
Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>