docs(rmm): document console struct in rmm boot manifest

This change adds documentation for the console_list and
console_info structures added to the RMM Boot Manifest v0.3.

Signed-off-by: Harry Moulton <harry.moulton@arm.com>
Change-Id: I3a4f9a4f1d34259bc69c0ab497cbfbc268d7a994
1 file changed