drm/amd/amdgpu/gfx_v7_0: Repair function names in the documentation

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

drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c:2126: warning: expecting prototype for gfx_v7_0_ring_emit_hdp(). Prototype was for gfx_v7_0_ring_emit_hdp_flush() instead
drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c:2262: warning: expecting prototype for gfx_v7_0_ring_emit_ib(). Prototype was for gfx_v7_0_ring_emit_ib_gfx() instead
drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c:3207: warning: expecting prototype for gfx_v7_0_ring_emit_vm_flush(). Prototype was for gfx_v7_0_ring_emit_pipeline_sync() instead

Cc: Alex Deucher <[e-mail]>
Cc: "Christian König" <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Sumit Semwal <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c

···
 }
 
 /**
- * gfx_v7_0_ring_emit_hdp - emit an hdp flush on the cp
+ * gfx_v7_0_ring_emit_hdp_flush - emit an hdp flush on the cp
  *
  * @ring: amdgpu_ring structure holding ring information
  *
···
  * IB stuff
  */
 /**
- * gfx_v7_0_ring_emit_ib - emit an IB (Indirect Buffer) on the ring
+ * gfx_v7_0_ring_emit_ib_gfx - emit an IB (Indirect Buffer) on the ring
  *
  * @ring: amdgpu_ring structure holding ring information
  * @job: job to retrieve vmid from
···
 }
 
 /**
- * gfx_v7_0_ring_emit_vm_flush - cik vm flush using the CP
+ * gfx_v7_0_ring_emit_pipeline_sync - cik vm flush using the CP
  *
  * @ring: the ring to emit the commands to
  *