sb/intel/i82801jx: Enable upper 128bytes of CMOS

The normal romcc bootblock uses this.

Change-Id: I60f735f703a9208911f5cc8a81930535e574644d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36755
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/southbridge/intel/i82801jx/bootblock.c

@@ -36,4 +36,7 @@ static void bootblock_southbridge_init(void)
 	/* Enable RCBA */
 	pci_write_config32(PCI_DEV(0, 0x1f, 0), RCBA,
 			(uintptr_t)DEFAULT_RCBA | 1);
+
+	/* Enable upper 128bytes of CMOS. */
+	RCBA32(0x3400) = (1 << 2);
 }