drm/amdgpu: Fix missing parameter descriptions in ih_v7_0.c

Rectifies kdoc warnings related to the 'ih' parameter in the
'ih_v7_0_get_wptr', 'ih_v7_0_irq_rearm', and 'ih_v7_0_set_rptr'
functions within the 'ih_v7_0.c' file.

Fixes the below with gcc W=1:
drivers/gpu/drm/amd/amdgpu/ih_v7_0.c:392: warning: Function parameter or member 'ih' not described in 'ih_v7_0_get_wptr'
drivers/gpu/drm/amd/amdgpu/ih_v7_0.c:432: warning: Function parameter or member 'ih' not described in 'ih_v7_0_irq_rearm'
drivers/gpu/drm/amd/amdgpu/ih_v7_0.c:458: warning: Function parameter or member 'ih' not described in 'ih_v7_0_set_rptr'

Fixes: 12443fc5 ("drm/amdgpu: Add ih v7_0 ip block support")
Cc: Likun Gao <Likun.Gao@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/ih_v7_0.c

@@ -378,9 +378,10 @@ static void ih_v7_0_irq_disable(struct amdgpu_device *adev)
 }
 
 /**
- * ih_v7_0_get_wptr - get the IH ring buffer wptr
+ * ih_v7_0_get_wptr() - get the IH ring buffer wptr
  *
  * @adev: amdgpu_device pointer
+ * @ih: IH ring buffer to fetch wptr
  *
  * Get the IH ring buffer wptr from either the register
  * or the writeback memory buffer.  Also check for
@@ -425,6 +426,7 @@ static u32 ih_v7_0_get_wptr(struct amdgpu_device *adev,
  * ih_v7_0_irq_rearm - rearm IRQ if lost
  *
  * @adev: amdgpu_device pointer
+ * @ih: IH ring to match
  *
  */
 static void ih_v7_0_irq_rearm(struct amdgpu_device *adev,
@@ -450,8 +452,7 @@ static void ih_v7_0_irq_rearm(struct amdgpu_device *adev,
  * ih_v7_0_set_rptr - set the IH ring buffer rptr
  *
  * @adev: amdgpu_device pointer
- *
- * Set the IH ring buffer rptr.
+ * @ih: IH ring buffer to set rptr
  */
 static void ih_v7_0_set_rptr(struct amdgpu_device *adev,
 			       struct amdgpu_ih_ring *ih)