Add support for Raspberry Pi 3 B plus

Copy both RPi3 B and RPi3 B Plus dtb files to enable
booting both the targets. This will avoid adding a seperate
rpi3-bplus makefile.

Signed-off-by: Philby John <philby.j@hcl.com>
Signed-off-by: Vv Ramya <ramyavv@hcl.com>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Joakim Bech <joakim.bech@linaro.org> # (rpi3b)

rpi3.mk

@@ -37,7 +37,8 @@ OPTEE_BIN_EXTRA1	?= $(OPTEE_PATH)/out/arm/core/tee-pager_v2.bin
 OPTEE_BIN_EXTRA2	?= $(OPTEE_PATH)/out/arm/core/tee-pageable_v2.bin
 
 LINUX_IMAGE		?= $(LINUX_PATH)/arch/arm64/boot/Image
-LINUX_DTB		?= $(LINUX_PATH)/arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b.dtb
+LINUX_DTB_RPI3_B	?= $(LINUX_PATH)/arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b.dtb
+LINUX_DTB_RPI3_BPLUS	?= $(LINUX_PATH)/arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b-plus.dtb
 MODULE_OUTPUT		?= $(ROOT)/module_output
 
 ################################################################################
@@ -163,7 +164,8 @@ buildroot: update_rootfs
 update_rootfs: arm-tf linux u-boot
 	@mkdir -p --mode=755 $(BUILDROOT_TARGET_ROOT)/boot
 	@mkdir -p --mode=755 $(BUILDROOT_TARGET_ROOT)/usr/bin
-	@install -v -p --mode=755 $(LINUX_DTB) $(BUILDROOT_TARGET_ROOT)/boot/bcm2710-rpi-3-b.dtb
+	@install -v -p --mode=755 $(LINUX_DTB_RPI3_B) $(BUILDROOT_TARGET_ROOT)/boot/bcm2710-rpi-3-b.dtb
+	@install -v -p --mode=755 $(LINUX_DTB_RPI3_BPLUS) $(BUILDROOT_TARGET_ROOT)/boot/bcm2710-rpi-3-b-plus.dtb
 	@install -v -p --mode=755 $(RPI3_BOOT_CONFIG) $(BUILDROOT_TARGET_ROOT)/boot/config.txt
 	@install -v -p --mode=755 $(LINUX_IMAGE) $(BUILDROOT_TARGET_ROOT)/boot/kernel8.img
 	@install -v -p --mode=755 $(ARM_TF_BOOT) $(BUILDROOT_TARGET_ROOT)/boot/armstub8.bin