docs: Add GIC600AE FVP model version information
docs: Add GIC600AE FVP model version information

Added GIC600AE FVP model version information.

Change-Id: I15d25fbdb8e09900976d5993032ec049f8db79f2
Signed-off-by: Manish V Badarkhe <d2342ad575f6bc1a5f5a5b89d6db0f72dd7e0e4c@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware