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/soc/intel/apollolake/Kconfig

@@ -113,7 +113,6 @@ config CHROMEOS
 config VBOOT
 	select VBOOT_SEPARATE_VERSTAGE
 	select VBOOT_MUST_REQUEST_DISPLAY
-	select VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT
 	select VBOOT_STARTS_IN_BOOTBLOCK
 	select VBOOT_VBNV_CMOS
 	select VBOOT_VBNV_CMOS_BACKUP_TO_FLASH