drm/radeon: allow unaligned shader loads on CIK

Set alignment mode to unaligned on CIK to align with amdgpu.  This is
needed for unaligned loads to work properly in mesa.  The current setting
requires dword alignment.

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>