cpu/intel/car: Drop remains of setup_stack_and_mtrrs()

Platforms have moved to POSTCAR_STAGE=y.

Change-Id: I79c87e546805dbe0a4c28ed95f4d12666734eb79
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30489
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/cpu/intel/car/romstage.c

@@ -50,9 +50,6 @@ asmlinkage void *romstage_main(unsigned long bist)
 		printk(BIOS_DEBUG, "Smashed stack detected in romstage!\n");
 	}
 
-	if (!IS_ENABLED(CONFIG_POSTCAR_STAGE))
-		return setup_stack_and_mtrrs();
-
 	platform_enter_postcar();
 
 	/* We do not return. */