UefiCpuPkg/FeaturesLib: Fix Haswell CPU hang with 50% throttling

Today's implementation only assumes SandyBridge CPU supports
Extended On-Demand Clock Modulation Duty Cycle.
Actually it is supported when CPUID.06h.EAX[5] == 1.

When platform requests 50% throttling, it causes value 1000b
set to the low-4 bits of IA32_CLOCK_MODULATION.
But the wrong code sets 1000b to bits[1-3] which causes assertion.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Jeff Fan <vanjeff_919@hotmail.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>