BaseTools: Rollback Filter out unused structure pcds

BaseTools: Rollback Filter out unused structure pcds

This reverts commit 51d17bb7b0da0d9c9e91c226f1982d7020f43795.
commit 51d17bb7b0da0d9c9e91c226f1982d7020f43795 adds new check
of Pcds in the platform unused library INF files.
It breaks the existing platform.
To avoid the impact, roll back this change first.

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