clover: use the unified check for c++11 instead of the gcc version number

clover: use the unified check for c++11 instead of the gcc version number

So far clover based its test for compiler support on the version of gcc,
while in reality support for c++11 is required. This patch replaces the
version check by the check unified for all modules that require c++11.

Reviewed-by: Emil Velikov <emil.velikov@collabora.com>