renesas: rzg: Add support to identify EK874 RZ/G2E board

Add support to identify Silicon Linux RZ/G2E evaluation kit (EK874).

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Change-Id: Id7bdbc9b0d25aa9af496d58d4bd5055579edc104
5 files changed