rcar_gen3: plat: Add initial D3 support

Add R-Car D3 SoC platform specifics. Driver, PFC, QoS, DDR init code
will be added separately.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
diff --git a/plat/renesas/rcar/bl2_secure_setting.c b/plat/renesas/rcar/bl2_secure_setting.c
index cbda1eb..7473df5 100644
--- a/plat/renesas/rcar/bl2_secure_setting.c
+++ b/plat/renesas/rcar/bl2_secure_setting.c
@@ -52,7 +52,7 @@
 	    /*        1: Reserved[R-Car E3]                                 */
 	    /* Bit10: SCEG Secure Core slave ports                          */
 	    /*        0: registers accessed from secure resource only       */
-#if RCAR_LSI == RCAR_E3
+#if (RCAR_LSI == RCAR_E3) || (RCAR_LSI == RCAR_D3)
 	{
 	SEC_SEL6, 0xFFFFFBFFU},
 #else