andes_spi: add andes_spi interface

andes_spi is an spi interface developed by Andes Tech.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
3 files changed