BaseTools: Fix Pcd Array changes build report issue.

BaseTools: Fix Pcd Array changes build report issue.

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1472

The Pcd Array feature changes the Pcd Default value
data structure which is used by build report. This
patch is going to update build report to adapt that change.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zhiju.Fan <zhijux.fan@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>