BaseTools AARCH64: move to unified GCC linker script

BaseTools AARCH64: move to unified GCC linker script

Drop the GCC AARCH64 specific linker script and use the new
unified one instead.

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>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18138 6f19259b-4bc3-4df7-8a09-765794883524