Remove CUDA host compiler consistency checks
Since CMake 2.8.10 the host compiler is set by CMake which effectively
broke our consistency checks. However, these checks are hard to
maintain, and even though CMake does not do any checks we are better off
without this code.
This commit removed the checks, unconditionally sets the
CUDA_HOST_COMPILER variable for CMake 2.8.9 and earlier - code that
should be removed when CMAke 2.8.10 is required.
Fixes #1248
Change-Id: I6c08b59642dd3b5d18c5fe5ac454f19c75718f6a