[U-Boot] ARM: rockchip: Add rv1108-elgin-r1 board support

[Philipp Tomsich]

> Add the initial support for Elgin R1 board, which is based on the
> RV1108 SoC and has the following features currently supported in
> U-Boot:
> 
> - UART
> - eMMC
> - USB
> 
> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
> ---
> 
>  arch/arm/dts/Makefile                   |  1 +
>  arch/arm/dts/rv1108-elgin-r1.dts        | 48 ++++++++++++++++
>  arch/arm/mach-rockchip/rv1108/Kconfig   |  6 ++
>  board/elgin/elgin_rv1108/Kconfig        | 15 +++++
>  board/elgin/elgin_rv1108/MAINTAINERS    |  6 ++
>  board/elgin/elgin_rv1108/Makefile       |  7 +++
>  board/elgin/elgin_rv1108/elgin_rv1108.c | 74 +++++++++++++++++++++++++
>  configs/elgin-rv1108_defconfig          | 58 +++++++++++++++++++
>  include/configs/elgin_rv1108.h          | 13 +++++
>  9 files changed, 228 insertions(+)
>  create mode 100644 arch/arm/dts/rv1108-elgin-r1.dts
>  create mode 100644 board/elgin/elgin_rv1108/Kconfig
>  create mode 100644 board/elgin/elgin_rv1108/MAINTAINERS
>  create mode 100644 board/elgin/elgin_rv1108/Makefile
>  create mode 100644 board/elgin/elgin_rv1108/elgin_rv1108.c
>  create mode 100644 configs/elgin-rv1108_defconfig
>  create mode 100644 include/configs/elgin_rv1108.h
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>