Build: Build and arrange partition static data

- Add a template to generate partition static data into
  dedicated source files. For the ns internal partition,
  manually add a source file for it.
- Put these data into a dedicated memory section, to
  prepare for partition loading.

Change-Id: Iad988608b04d2db9f5f43e7528f3ef21c1252f31
Signed-off-by: Mingyang Sun <mingyang.sun@arm.com>