Blender Git Loki

Fix Cycles CUDA kernels for Ampere not building with CUDA 11

Running Blender on Ampere cards was already possible with ptx, this fix is
needed to support building CUDA binaries.

Note the CUDA version used for official Blender builds is still 10, this is
merely the change to make it possible for those using CUDA 11 and specifying
the sm_8x kernels to be compiled.

Found by Milan Jaros.