cuda.bbclass: update to align with SDK builds
cuda.bbclass: update to align with SDK builds

This is mostly cleanup to align with the CUDA language
support that has been in CMake since version 3.8 - setting
the correct environment variables with the correct values
makes CMake's auto-discovery work better, so we can
remove much of the toolchain config file settings that
were there as workarounds.

The settings related to using FindCUDA are kept, for now.

Signed-off-by: Matt Madison <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@madison.systems>

madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra