feat(neoverse-rd): add scope for SGI-575

As SGI-575 would need a dedicated scope for use, define the scope
'sgi575' under the subsection within Neoverse-RD platforms.

Change-Id: I872dc3bceace5c3358cde24fff1c4c17207ec962
Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
1 file changed