[CUDA][HIP] Do not treat host var address as constant in device compilation

Currently clang treats host var address as constant in device compilation,
which causes const vars initialized with host var address promoted to
device variables incorrectly and results in undefined symbols.

This patch fixes that.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D118153

Fixes: SWDEV-309881

Change-Id: I0a69357063c6f8539ef259c96c250d04615f4473