vboot2: load decompressed stage directly to load address

this change allows vboot_load_stage to load a decompressed stage directly to the
load address without using the cbfs cache.

BUG=None
TEST=Booted Nyan Blaze.
BRANCH=None
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>

Original-Change-Id: I76530276ff9a87b44f98a33f2c34bd5b2de6888f
Original-Reviewed-on: https://chromium-review.googlesource.com/219028
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Daisuke Nojiri <dnojiri@chromium.org>
Original-Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
(cherry picked from commit 0ad6f7fee9df31e1b35d4df9a8c373516416a235)

Change-Id: I7abdbdda0cc549894dfb9d599a576bba0a4fadfc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8883
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/include/cbfs.h b/src/include/cbfs.h
index 5297230..9aa2c96 100644
--- a/src/include/cbfs.h
+++ b/src/include/cbfs.h
@@ -55,6 +55,7 @@
 void *cbfs_load_optionrom(struct cbfs_media *media, uint16_t vendor,
 			  uint16_t device, void * dest);
 void *cbfs_load_stage(struct cbfs_media *media, const char *name);
+void *cbfs_load_stage_by_offset(struct cbfs_media *media, ssize_t offset);
 
 /* Simple buffer for streaming media. */
 struct cbfs_simple_buffer {