ASoC: Intel: Skylake: Fix memory leak in nhlt init

During skl_nhlt_init(), acpi obj pointer is allocated and never
freed and remap address is not unmapped.

To fix this we should release the ACPI obj and also unmap the
nhlt address during cleanup of driver.

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>