BaseTools GCC: add unified GCC linker script for all archs and versions

BaseTools GCC: add unified GCC linker script for all archs and versions

This unifies all GCC linker scripts into a single parametrised GCC
linker script that can be used for all GCC versions and architectures.

The two parameters that can be set on the linker command line are:
- PECOFF_HEADER_SIZE, this is a build time property of GenFw, but
  its value is different between 32-bit and 64-bit;
- common-page-size, this can be set using -z on the ld command line,
  and controls the value of the COMMONPAGESIZE constant when used in
  a linker script. This value is used for the minimum section alignment.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Liming Gao <liming.gao@intel.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18135 6f19259b-4bc3-4df7-8a09-765794883524