ARM: PRIMA2: add CSR SiRFmarco device tree .dts

SiRFmarco is a dual-core cortex-a9 SMP SoC from CSR. this patch
adds the .dtsi and a basic evb board .dts for it.

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>