ARM: dts: add init dts file for CSR atlas7 SoC

CSR atlas7 uses Network on Chip(NoC) bus architecture, there are dozens
of MARCOs, in each MARCO, there are dozens of hardware modules.

Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Hao Liu <Hao.Liu@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>