arm: mach-k3: sysfw-loader: Add support for rom loading sysfw image

arm: mach-k3: sysfw-loader: Add support for rom loading sysfw image

Starting J7200 SoC, ROM supports for loading sysfw directly from boot
image. In such cases, SPL need not load sysfw from boot media, but need
to receive boot notification message from sysfw. So separate out
remoteproc calls for system controller from sysfw loader and just
receive the boot notification if sysfw is already loaded.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Suman Anna <s-anna@ti.com>