lib/prog_loaders: Move argument selection into selfload

Set the payload argument in selfload, as other (non self) payloads, are
going to set a different argument.

Change-Id: I994f604fc4501e0e3b00165819f796b1b8275d8c
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/25861
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
4 files changed