forked from Mirrors/opensbi

Introduce SBI Message Proxy (MPXY) framework which allows platform specific code or drivers to register message protocol specific channels. This framework enables the supervisor software to send messages belonging to different message protocols via OpenSBI firmware. Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com> Co-developed-by: Himanshu Chauhan <hchauhan@ventanamicro.com> Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com> Co-developed-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com>