drm/amd/amdgpu/iceland_ih: Add missing function param descriptions for 'ih' and 'entry'

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/amd/amdgpu/iceland_ih.c:191: warning: Function parameter or member 'ih' not described in 'iceland_ih_get_wptr'
 drivers/gpu/drm/amd/amdgpu/iceland_ih.c:223: warning: Function parameter or member 'ih' not described in 'iceland_ih_decode_iv'
 drivers/gpu/drm/amd/amdgpu/iceland_ih.c:223: warning: Function parameter or member 'entry' not described in 'iceland_ih_decode_iv'
 drivers/gpu/drm/amd/amdgpu/iceland_ih.c:253: warning: Function parameter or member 'ih' not described in 'iceland_ih_set_rptr'

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -179,6 +179,7 @@ static void iceland_ih_irq_disable(struct amdgpu_device *adev)
  * iceland_ih_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 (VI).  Also check for
@@ -213,6 +214,8 @@ static u32 iceland_ih_get_wptr(struct amdgpu_device *adev,
  * iceland_ih_decode_iv - decode an interrupt vector
  *
  * @adev: amdgpu_device pointer
+ * @ih: IH ring buffer to decode
+ * @entry: IV entry to place decoded information into
  *
  * Decodes the interrupt vector at the current rptr
  * position and also advance the position.
@@ -245,6 +248,7 @@ static void iceland_ih_decode_iv(struct amdgpu_device *adev,
  * iceland_ih_set_rptr - set the IH ring buffer rptr
  *
  * @adev: amdgpu_device pointer
+ * @ih: IH ring buffer to set rptr
  *
  * Set the IH ring buffer rptr.
  */