mainboard: Add preliminary support for A10-based Cubieboard

Add a minimal infrastructure which initializes the system clocks
and serial console.

Change-Id: I768ede6ccf8674ffe9fecd8925cec89768209cab
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4553
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
7 files changed