drm/amdgpu: use doorbell mgr for MES kernel doorbells

This patch:
- Removes the existing doorbell management code, and its variables
  from the doorbell_init function, it will be done in doorbell
  manager now.
- uses the doorbell page created for MES kernel level needs (doorbells
  for MES self tests)
- current MES code was allocating MES doorbells in MES process context,
  but those were getting written using kernel doorbell calls. This patch
  instead allocates a MES kernel doorbell for this (in add_hw_queue).

V2: Create an extra page of doorbells for MES during kernel doorbell
    creation (Alex)
V4: Move MES doorbell size and page offset objects in this patch from
    patch 6.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Reviewed-by: Christian Koenig <christian.koenig@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_mes.h

@@ -27,6 +27,7 @@
 #include "amdgpu_irq.h"
 #include "kgd_kfd_interface.h"
 #include "amdgpu_gfx.h"
+#include "amdgpu_doorbell.h"
 #include <linux/sched/mm.h>
 
 #define AMDGPU_MES_MAX_COMPUTE_PIPES        8
@@ -128,6 +129,11 @@ struct amdgpu_mes {
 	int                             (*kiq_hw_init)(struct amdgpu_device *adev);
 	int                             (*kiq_hw_fini)(struct amdgpu_device *adev);
 
+	/* MES doorbells */
+	uint32_t			db_start_dw_offset;
+	uint32_t			num_mes_dbs;
+	unsigned long			*doorbell_bitmap;
+
 	/* ip specific functions */
 	const struct amdgpu_mes_funcs   *funcs;
 };