[coreboot] [PATCH]Fix ACPI in HIGH-and-LOW tables configuration

[Patrick Georgi]

Hi,

I messed up and added some "harmless" code right before pushing this change.
Just that it wasn't harmless. I'm sorry.

Anyway, with this patch, ACPI works again for setups with both 
HAVE_HIGH_TABLES and HAVE_LOW_TABLES, as the RSDP contains valid data now 
(without it the RSDT is bogus: it is read out before it is written)

Signed-off-by: Patrick Georgi

Patrick