drm/vmwgfx: Remove the dedicated memory accounting

vmwgfx shared very elaborate memory accounting with ttm. It was moved
from ttm to vmwgfx in change
f07069da6b ("drm/ttm: move memory accounting into vmwgfx v4")
but because of complexity it was hard to maintain. Some parts of the code
weren't freeing memory correctly and  some were missing accounting all
together. While those would be fairly easy to fix the fundamental reason
for memory accounting in the driver was the ability to invoke shrinker
which is part of TTM code as well (with support for unified memory
hopefully coming soon).

That meant that vmwgfx had a lot of code that was either unused or
duplicating code from TTM. Removing this code also prevents excessive
calls to global swapout which were common during memory pressure
because both vmwgfx and TTM would invoke the shrinker when memory
usage reached half of RAM.

Fixes: f07069da6b ("drm/ttm: move memory accounting into vmwgfx v4")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-2-zack@kde.org

drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c

@@ -324,22 +324,3 @@ void vmw_cmdbuf_res_man_destroy(struct vmw_cmdbuf_res_manager *man)
 	kfree(man);
 }
 
-/**
- * vmw_cmdbuf_res_man_size - Return the size of a command buffer managed
- * resource manager
- *
- * Returns the approximate allocation size of a command buffer managed
- * resource manager.
- */
-size_t vmw_cmdbuf_res_man_size(void)
-{
-	static size_t res_man_size;
-
-	if (unlikely(res_man_size == 0))
-		res_man_size =
-			ttm_round_pot(sizeof(struct vmw_cmdbuf_res_manager)) +
-			ttm_round_pot(sizeof(struct hlist_head) <<
-				      VMW_CMDBUF_RES_MAN_HT_ORDER);
-
-	return res_man_size;
-}