Creating two I2S instances for Stoney/cz platforms.

v2: squash in:
"drm/amdgpu/acp: Fix slab-out-of-bounds in mfd_add_device in acp_hw_init"
From Daniel Kurtz <djkurtz@chromium.org>.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>