refactor(neoverse-rd): refactor scope for Neoverse RD platforms

As sgi has migrated to neoverse_rd, the scope variables would need
update. Therefore, remove the deprecated 'sgi' scope variable and
introduce the new scope variable 'neoverse-rd' to be used for any common
platform changes associated with Neoverse Reference Design platforms.

Change-Id: I5052e4573bdc7df3e6f4257146d716edd2585452
Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
1 file changed