fwts needs to read from external data for ACPI emulation

This is similar to enable "acpiexec -fi <namespace init file>"

When FWTS reads from hardware in OpRegion in DSDT/SSDTs, the values are zeros because no hardware to be read in acpica's emulation mode.

This can miss some code paths. For example, by providing different default values for PCHS, the below ACPI devices can be changed.

    OperationRegion (PNVA, SystemMemory, PNVB, PNVL)
    Field (PNVA, AnyAcc, Lock, Preserve)
    {
        PCHS, 16,
    }
    ...
    If ((PCHS == 0x02))
    {
         Device (ABCD)
         ...
    } Else {
         Device (EFGH)
         ...
    }
or
    Device (XYZ)
    {
        Method (_HID) {
            If ((PCHS == 0x02))
                return "1234567890"
            return "0987654321"
        }
    }