tegra124: Add a custom bootblock implementation.

This implementation is the same as the general one except that it removes all
the things that don't work on an ARMv4.

Change-Id: I1108a79cc656b26f7d48df20aef3016cf5ae3182
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171019
Reviewed-by: Ronald Minnich <rminnich@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit d1436288d3b025af27a8d28ba94b589940ead504)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6713
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/soc/nvidia/tegra124/bootblock.c

@@ -17,8 +17,20 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <bootblock_common.h>
+#include <arch/hlt.h>
+#include <arch/stages.h>
+#include <cbfs.h>
+#include <console/console.h>
 
-void bootblock_cpu_init(void)
+void main(void)
 {
+	void *entry;
+
+	if (CONFIG_BOOTBLOCK_CONSOLE)
+		console_init();
+
+	entry = cbfs_load_stage(CBFS_DEFAULT_MEDIA, "fallback/romstage");
+
+	if (entry) stage_exit(entry);
+	hlt();
 }