RISCV: modify arch_prog_run to handle payloads correctly.

Unlike the other stages, the payload requires virtual memory to be set up
and also a privelege level change.

Change-Id: Ibbe2a55f7719d917f121a53a17c6d90e6b2ab3d1
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/11699
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
1 file changed