Incremental build time

Signed-off-by: Ashraf Ali S <[email protected]>

Signed-off-by: Ashraf Ali S <[email protected]>

Below are the comments from V3 patch. and this PR will address those.

Besides the PCD default value, I think there are still 2 more things
need to check. These 2 things could impact the output of the
PcdValueInit.exe.

1. Macros definition in BuildOption
There would be a case that the Macros are used in Structure Pcd's
definition in header file. User can change the structure pcd's struct
def via changing the Macro value from command line or dsc file.

2. The header file list defined in DEC
The [Includes] section in dec list folder that contains the structure
pcd definition header file. There may be case that user changes the
folder under [Includes] to change the header file to change the
structure pcd struct definition.

Signed-off-by: Ashraf Ali S <[email protected]>