Make GPU characteristics flags specific to Linux code only. The
rest of driver is moved to using nvgpu_is_enabled() API.
JIRA NVGPU-259
Change-Id: I46a5a90bb34f170e9e755e7683be142ed6b18cce
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1583992
GVS: Gerrit_Virtual_Submit