drm/amdgpu/sdma: use "*" adjacent to data name

drm/amdgpu/sdma: use "*" adjacent to data name

When declaring pointer data, the "*" symbol should be used adjacent to
the data name as per the coding standards. This resolves following
issues reported by checkpatch script:
	ERROR: "foo *   bar" should be "foo *bar"
	ERROR: "foo * bar" should be "foo *bar"
	ERROR: "foo*            bar" should be "foo *bar"
	ERROR: "(foo*)" should be "(foo *)"

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>