Raspberry Pi 3 Model B+ support

arch/arm/Kconfig

arch/arm/core/aarch64/Kconfig

arch/arm/core/aarch64/smp.c

arch/arm/include/aarch64/exc.h

boards/arm/raspi3/Kconfig.board

boards/arm/raspi3/Kconfig.defconfig

boards/arm/raspi3/board.cmake

boards/arm/raspi3/raspi3.dts

boards/arm/raspi3/raspi3.yaml

boards/arm/raspi3/raspi3_defconfig

drivers/serial/uart_pl011.c

drivers/timer/Kconfig

...indings/interrupt-controller/brcm,bcm2835-armctrl-ic.yaml

dts/bindings/interrupt-controller/brcm,bcm2835-l1-intc.yaml

dts/bindings/serial/arm,raspi3.yaml

include/arch/arm/aarch64/scripts/linker.ld

soc/arm/bcm2837/CMakeLists.txt

soc/arm/bcm2837/Kconfig.defconfig

soc/arm/bcm2837/Kconfig.soc

soc/arm/bcm2837/README.md