fb/gk20a: fix setting of large page size bit

Commit "ltc/gf100-: fix cbc issues on certain boards" moved the setting
of the large page size bit from bar/nvc0 to fb/nvc0. GK20A uses its own
FB device and the change was thus not applied to it - fix this.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
[DEBUG] Add channel dumping functions for NVEA
doc
graph/nvc0: add support for netlist firmwares

NVIDIA is releasing some GPU firmwares for the Tegra SoCs under
linux-firmware. The release format is a single file (called a netlist)
containing all the firmwares relevant to a GPU, which must thus be
extracted. This patch adds support for parsing the netlist and loading
the firmwares for the NVC0 family of GPUs, falling back to the previous
firmware lookup method is no netlist was already loaded.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
platform: support for netlist firmwares

Netlists released by NVIDIA are made of a single file containing
firmwares that can potentially be used across different engines. It
therefore makes most sense to load a netlist once before engines are
probed and have them duplicate their firmwares so the netlist can
be freed at the end of probe.

This patch implements this mechanism and adds the lookup data for GK20A.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
[HACK] add gk20a instmem

This is a gazillion times faster, but requires to invalidate the
GPU L2 (probably at a better place than this!)
Revert "[HACK] add gk20a instmem"

This reverts commit c9eeb89a4daf95f34b70d659f0eb467c5c606e2b.
fb/ramgk20a: use mm_nodes

This is how VRAM objects are defined on other GPUs, and this saves us
from caveats when mapping large pages.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
fb/ramgk20a: support IOMMU if present

Tegra SoCs come with an IOMMU that can make physically non-contiguous
regions of memory appear contiguous to the GPU. This patch adds support
for this unit if present. This greatly optimizes memory usage and allows
GK20A to perform without CMA.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>