video: tegra: host: gk20a: Don't use private nvhost headers

video: tegra: host: gk20a: Don't use private nvhost headers

This patch modifies the code so that private nvhost headers are never
included inside the gk20a driver. The public header is still used and
hence this patch leaves some dependencies against nvhost driver.

Change-Id: I599930b379af7679a0cdc06a0b5632024503f8e3
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/383710
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>