gpu: nvgpu: change unnamed structs to named structs

Following changes are made in this patch.
1) Change unnamed structs within gpu_ops to named structs
with the prefix gops_*.

2) Each named struct gops_ are moved into a separate gops specific file
under include/nvgpu/gops/

3) struct gpu_ops is moved into a separate file include/nvgpu/gpu_ops.h
and all other dependent struct gops_* are included in this header.

4) Direct references to include/nvgpu/gops are removed from files as its enough
to include gk20a.h.

Change-Id: Ieb22cb853be567e3bef14f5f8a04674eebd902ea
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2398776
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-misra <svc-mobile-misra@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Rajesh Devaraj <rdevaraj@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

userspace/units/init/nvgpu-init.c

@@ -32,7 +32,6 @@
 #include <nvgpu/posix/posix-fault-injection.h>
 #include <os/posix/os_posix.h>
 #include <nvgpu/dma.h>
-#include <nvgpu/gops_mc.h>
 
 /* for get_litter testing */
 #include "hal/init/hal_gv11b_litter.h"