cbfs/vboot: remove firmware component support

The Chrome OS verified boot path supported multiple CBFS
instances in the boot media as well as stand-alone assets
sitting in each vboot RW slot. Remove the support for the
stand-alone assets and always use CBFS accesses as the
way to retrieve data.

This is implemented by adding a cbfs_locator object which
is queried for locating the current CBFS. Additionally, it
is also signalled prior to when a program is about to be
loaded by coreboot for the subsequent stage/payload. This
provides the same opportunity as previous for vboot to
hook in and perform its logic.

BUG=chromium:445938
BRANCH=None
TEST=Built and ran on glados.
CQ-DEPEND=CL:307121,CL:31691,CL:31690

Change-Id: I6a3a15feb6edd355d6ec252c36b6f7885b383099
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/12689
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/lib/prog_loaders.c b/src/lib/prog_loaders.c
index a5598c7..e27eca1 100644
--- a/src/lib/prog_loaders.c
+++ b/src/lib/prog_loaders.c
@@ -33,6 +33,20 @@
 /* Only can represent up to 1 byte less than size_t. */
 const struct mem_region_device addrspace_32bit = MEM_REGION_DEV_INIT(0, ~0UL);
 
+int prog_locate(struct prog *prog)
+{
+	struct cbfsf file;
+
+	cbfs_prepare_program_locate();
+
+	if (cbfs_boot_locate(&file, prog_name(prog), NULL))
+		return -1;
+
+	cbfs_file_data(prog_rdev(prog), &file);
+
+	return 0;
+}
+
 void run_romstage(void)
 {
 	struct prog romstage =