docs: change FVP argument in RME configuration

In RME documentation use "bp.secure_memory=0" to disable TZC,
and avoid conflicts with SPM in 4-world configuration.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I532bca8ab3bd3e6d4f18b5aa7e848c533e016f39
1 file changed