vboot: remove old vboot_fill_handoff function header

This function was removed in CB:33535.

BUG=b:124141368
TEST=make clean && make runtests
BRANCH=none

Change-Id: Ifded75319c92dcbb4befbb3fbecc1cd2df8a9ad0
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37588
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/security/vboot/misc.h

@@ -52,11 +52,6 @@ static inline bool vboot_is_gbb_flag_set(enum vb2_gbb_flag flag)
 int vboot_locate_firmware(const struct vb2_context *ctx,
 			  struct region_device *fw);
 
-/*
- * Source: security/vboot/vboot_handoff.c
- */
-void vboot_fill_handoff(void);
-
 /*
  * Source: security/vboot/bootmode.c
  */