ld -r -o /usr/src/nvidia-381.22/nvidia-modeset/nv-modeset-interface.o
/usr/src/nvidia-381.22/nvidia-modeset/nvidia-modeset-linux.o
      LD [M]  /usr/src/nvidia-381.22/nvidia.o
      LD [M]  /usr/src/nvidia-381.22/nvidia-uvm.o
      LD [M]  /usr/src/nvidia-381.22/nvidia-modeset.o
      LD [M]  /usr/src/nvidia-381.22/nvidia-drm.o
      Building modules, stage 2.
      MODPOST 4 modules
    FATAL: modpost: GPL-incompatible module nvidia-drm.ko uses GPL-only symbol
'refcount_inc'
    make[2]: *** [__modpost] Error 1
    make[1]: *** [modules] Error 2
    make[1]: Leaving directory `/usr/src/kernels/linux-4.11'
    make: *** [modules] Error 2


We need:
commit d557d1b58b3546bab2c5bc2d624c5709840e6b10
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date:   Thu May 4 15:51:03 2017 -0700

    refcount: change EXPORT_SYMBOL markings