security/vboot: Removed vboot_prepare from vboot_locator

When prog_locate() is called in the stage VBOOT is starting from and the
image to be loaded is not the target image vboot_prepare() may be called
too early.

To prevent this vboot_prepare() is removed from the vboot_locator
structure. This allows more control over the start of the vboot logic.

To clarify the change the vboot_prepare() has been renamed to
vboot_run_logic() and calls to initialize vboot have been added at the
following places:

postcar_loader: when VBOOT starts in ROMSTAGE
romstage_loader: when VBOOT starts in BOOTBLOCK
ramstage_loader: when VBOOT starts in ROMSTAGE

BUG=N/A
TEST=tested on facebook fbg1701

Change-Id: Id5e8fd78458c09dd3896bfd142bd49c2c3d686df
Signed-off-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36543
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/lib/prog_loaders.c

@@ -30,6 +30,7 @@
 #include <symbols.h>
 #include <timestamp.h>
 #include <fit_payload.h>
+#include <security/vboot/vboot_common.h>
 
 /* Only can represent up to 1 byte less than size_t. */
 const struct mem_region_device addrspace_32bit =
@@ -59,6 +60,8 @@ void run_romstage(void)
 	struct prog romstage =
 		PROG_INIT(PROG_ROMSTAGE, CONFIG_CBFS_PREFIX "/romstage");
 
+	vboot_run_logic();
+
 	if (prog_locate(&romstage))
 		goto fail;
 
@@ -135,6 +138,8 @@ void run_ramstage(void)
 	    !CONFIG(NO_STAGE_CACHE))
 		run_ramstage_from_resume(&ramstage);
 
+	vboot_run_logic();
+
 	if (prog_locate(&ramstage))
 		goto fail;