selfboot: Report correct entry point address in debug message.

selfboot: Report correct entry point address in debug message.

Entry point in payload segment header is a 64 bit integer (ntohll). The debug
message is currently reading that as a 32 bit integer (which will produce
00000000 for most platforms).

Change-Id: I931072bbb82c099ce7fae04f15c8a35afa02e510
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2535
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)