Fix rom_reserve()/rom_confirm() for CSM oprom dispatch

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Don't calibrate TSC if PMTIMER is already set up

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Move find_pmtimer() to ACPI table setup where it logically belongs

We don't have the ordering dependency with timer_setup() any more.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Use find_pmtimer() after copying Xen ACPI tables

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Use find_pmtimer() after copying coreboot ACPI tables

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Unify return path for CSM to go via csm_return()

This allows us to keep the entry_csm code simple, and ensures that we
consistently do things like saving the PIC mask (and later setting
UmbStart) on the way back to UEFI.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>