arm: add support to corstone1000 platform

arm: add support to corstone1000 platform

Corstone1000 is a platform from arm, which includes pre
verified Corstone SSE710 sub-system that combines Cortex-A and
Cortex-M processors [0].

This code adds the support for the Cortex-A35 implementation
at host side, it contains also the necessary bits to support
the Corstone 1000 FVP (Fixed Virtual Platform) [1] and also the
FPGA MPS3 board implementation of this platform. [2]

0: https://developer.arm.com/documentation/102360/0000
1: https://developer.arm.com/tools-and-software/open-source-software/arm-platforms-software/arm-ecosystem-fvps
2: https://developer.arm.com/documentation/dai0550/c/

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>