doc: board: ti: Add missing firmware for BB-AI64

The details of the sysfw.itb from the R5 build that
also needs to be copied as part of the target images
is missing, but is included in the image formats a
little further down, so add it to the instructions.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Acked-by: Nishanth Menon <nm@ti.com>
1 file changed