Add O2Micro/BayHubTech chip 8520 subversion B1 SD3.0 support.
Add O2Micro/BayHubTech chip 8620 and 8621 SD3.0 support
Enable Led function of 8520 chip.

Signed-off-by: Peter Guo <peter.guo@bayhubtech.com>
Signed-off-by: Adam Lee <adam.lee@canonical.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>