docs/fvp: update SGI and RD FVP list
docs/fvp: update SGI and RD FVP list

Update SGI-575, RD-E1-Edge and RD-N1-Edge FVP versions to 11.10/36 and
add RD-N1-Edge-Dual to the list of supported Arm Fixed Virtual
Platforms.

Change-Id: I9e7e5662324eeefc80d799ca5341b5bc4dc39cbb
Signed-off-by: Vijayenthiran Subramaniam <762698363137248267721733483077a93dddd540@arm.com>

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