rcar_gen3: plat: Dump EL3 interrupt error registers

Since the interrupts are handled in EL3, dump the EL3 error registers
in case an error happens.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
diff --git a/plat/renesas/rcar/aarch64/plat_helpers.S b/plat/renesas/rcar/aarch64/plat_helpers.S
index df1664d..ae0d675 100644
--- a/plat/renesas/rcar/aarch64/plat_helpers.S
+++ b/plat/renesas/rcar/aarch64/plat_helpers.S
@@ -217,6 +217,8 @@
 	 * ---------------------------------------------
 	 */
 func plat_report_exception
+	/* Switch to SP_EL0 */
+	msr	spsel, #0
 #if IMAGE_BL2
 	mov	w1, #FIQ_SP_EL0
 	cmp	w0, w1