Make the MUSCA_A1 target TF-M compatible by doing the following:
    - Add flash, region definitions, and preprocessed image macros from
      TF-M (at version 6e7be077eabe "Core: Add lifecycle API")
    - Update the MUSCA_A1 linker script to create a flash image
      compatible with TF-M.
    - Update the tfm/bin_utils/assemble.py signing script to work with
      preprocessed image macros rather than flat C pre-processor defines

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>
Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>