linuxPackages.nvidia_x11_legacy340: fix cr4 references

Patch was copied from here:
https://devtalk.nvidia.com/default/topic/813458/linux-4-0-rc1-346-47-build-error-_cr4-functions-fix/

Reference to kernel change, also noted in the forum post:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/x86/include/asm/paravirt.h?id=1e02ce4cccdcb9688386e5b8d2c9fa4660b45389