intel/car: Use common TS_START_ROMSTAGE

This timestamp also got unintentionally removed from some
boards as they were transformed to use common romstage entry.

Change-Id: I12be278a674f9a2ea073b170a223c41c7fc01a94
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34970
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/car/romstage.c

@@ -87,6 +87,8 @@ asmlinkage void bootblock_c_entry_bist(uint64_t base_timestamp, uint32_t bist)
 
 asmlinkage void car_stage_entry(void)
 {
+	timestamp_add_now(TS_START_ROMSTAGE);
+
 	/* Assumes the hardware was set up during the bootblock */
 	console_init();