this patch adds tick timer, smp entries and generic DT machine
for SiRFmarco dual-core SMP chips.

with the added marco, we change the defconfig, using the same
defconfig, we get a zImage which can work on both prima2 and
marco.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Mark Rutland <mark.rutland@arm.com>