Remove unneeded include paths in PLAT_INCLUDES

Also, update platform_def.h guidelines about includes in the porting
guide.

Change-Id: I1ae338c9dd3242b309f6d53687ba2cb755d488c3
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/plat/renesas/rcar/platform.mk b/plat/renesas/rcar/platform.mk
index 629a3cf..a54a60a 100644
--- a/plat/renesas/rcar/platform.mk
+++ b/plat/renesas/rcar/platform.mk
@@ -306,8 +306,7 @@
 include drivers/staging/renesas/rcar/pfc/pfc.mk
 include lib/libfdt/libfdt.mk
 
-PLAT_INCLUDES	:=	-Iinclude/common/tbbr			\
-			-Idrivers/staging/renesas/rcar/ddr	\
+PLAT_INCLUDES	:=	-Idrivers/staging/renesas/rcar/ddr	\
 			-Idrivers/staging/renesas/rcar/qos	\
 			-Idrivers/renesas/rcar/iic_dvfs		\
 			-Idrivers/renesas/rcar/board		\