drm/etnaviv: Drop unused data member from the etnaviv_gem_object structure

Referencing the 'struct etnaviv_gpu *' by every etnaviv GEM BO is weird.
Drop it and drop yet another unused data field, namely 'access'.

Memory footprint of etnaviv GEM BOs reduced.

Signed-off-by: Sui Jingfeng <[e-mail]>
Signed-off-by: Lucas Stach <[e-mail]>

drivers/gpu/drm/etnaviv/etnaviv_gem.h

···
 	u32 flags;
 
 	struct list_head gem_node;
-	struct etnaviv_gpu *gpu;     /* non-null if active */
 	atomic_t gpu_active;
-	u32 access;
 
 	struct page **pages;
 	struct sg_table *sgt;