vboot: remove VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT option

With CL:1940398, this option is no longer needed.  Recovery
requests are not cleared until kernel verification stage is
reached.  If the FSP triggers any reboots, recovery requests
will be preserved.  In particular:

- Manual requests will be preserved via recovery switch state,
  whose behaviour is modified in CB:38779.
- Other recovery requests will remain in nvdata across reboot.

These functions now only work after verstage has run:
  int vboot_check_recovery_request(void)
  int vboot_recovery_mode_enabled(void)
  int vboot_developer_mode_enabled(void)

BUG=b:124141368, b:35576380
TEST=make clean && make test-abuild
BRANCH=none

Change-Id: I52d17a3c6730be5c04c3c0ae020368d11db6ca3c
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38780
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/security/vboot/Kconfig

@@ -156,14 +156,6 @@ config VBOOT_RETURN_FROM_VERSTAGE
 	  reused by the succeeding stage. This is useful if a RAM space is too
 	  small to fit both the verstage and the succeeding stage.
 
-config VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT
-	bool
-	default n
-	help
-	  This option ensures that the recovery request is not lost because of
-	  reboots caused after vboot verification is run. e.g. reboots caused by
-	  FSP components on Intel platforms.
-
 config VBOOT_MUST_REQUEST_DISPLAY
 	bool
 	default y if VGA_ROM_RUN