scripts: Extend create-binary-archive.sh for unified binary tar ball

scripts: Extend create-binary-archive.sh for unified binary tar ball

This patch extends/revamps create-binary-archive.sh to allow creating
unified binary tar ball containing both RV32 and RV64 images. Users
can also create "RV32 only" or "RV64 only" tar balls as well.

Few example commands are as follows:
./scripts/create-binary-archive.sh (Build both RV32 & RV64 images)
./scripts/create-binary-archive.sh -x 32 (Build RV32 only images)
./scripts/create-binary-archive.sh -x 64 (Build RV64 only images)

Signed-off-by: Anup Patel <anup.patel@wdc.com>