This patch adds the driver to interact with the different
APIs exposed by the SECO using a shared Messaging Unit.
The driver exposes some char devices in user space allowing
a user to send message to the SECO and read its response.
The driver uses the mailbox framework instead of directly
configuring the MU.
Signed-off-by: Silvano di Ninno
Signed-off-by: Franck LENORMAND
Acked-by: Dong Aisheng
Acked-by: Leonard Crestez