tools/power/x86/intel-speed-select: Fix invalid core mask

The core mask display is wrong in some cases. This is showing more
cpus than the mask has. This is because mask is 64 bit but it used
with BIT() macro to get the presence of CPU which doesn't support
unsigned long long. Added a new macro for BIT_ULL and use that
to get the presence of a CPU.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>