doc,kas: Update the FVP end user license title

From "Accept the END USER LICENSE AGREEMENT FOR ARM SOFTWARE
DEVELOPMENT TOOLS" to "Accept the END USER LICENSE AGREEMENT FOR ARM
ECOSYSTEM MODELS"
Ref: https://developer.arm.com/downloads/-/arm-ecosystem-fvps/eula



And all screenshots include the license information are also updated

Signed-off-by: Jun Wu <Jun.Wu@arm.com>