mb/lenovo/t60/romstage: Remove unused include

This commit follows up on commit 8b7a1614 with Change-Id:
I73c557d6ef009fb2cac35fdea500dee76f525330 ("src/mainboard: Remove
unneeded include <arch/io.h>").

Change-Id: I7f307bf5b6cdcfebe1a290ce344b962fcecc8781
Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33366
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/lenovo/t60/romstage.c

@@ -18,7 +18,6 @@
 // __PRE_RAM__ means: use "unsigned" for device, not a struct.
 
 #include <stdint.h>
-#include <arch/io.h>
 #include <cf9_reset.h>
 #include <device/pnp_ops.h>
 #include <device/pci_ops.h>