util/riscvtools: Add script that turns coreboot.rom into an ELF

This is required because SPIKE doesn't support loading flat files yet.

Change-Id: If745d78712ca8108b5dcc21591201bc2d3f70b86
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/14964
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

util/riscvtools/spike-elf.ld

@@ -0,0 +1,11 @@
+/* See make-spike-elf.sh */
+
+ENTRY(_start);
+SECTIONS
+{
+	. = 0x80000000;
+	_start = .;
+	.data : {
+		*(.data)
+	}
+}