platform/x86: thinkpad_acpi: Fix Embedded Controller access on X380 Yoga

platform/x86: thinkpad_acpi: Fix Embedded Controller access on X380 Yoga

On the X380 Yoga, the `ECRD` and `ECWR` ACPI objects cannot be used for
accessing the Embedded Controller: instead of a method that reads from
the EC's memory, `ECRD` is the name of a location in high memory. This
meant that trying to call them would fail with the following message:

  ACPI: \_SB.PCI0.LPCB.EC.ECRD: 1 arguments were passed to a non-method
  ACPI object (RegionField)

With this commit, it is now possible to access the EC and read
temperature and fan speed information. Note that while writes to the
HFSP register do go through (as indicated by subsequent reads showing
the new value), the fan does not actually change its speed.

Signed-off-by: Daniel Bertalan <dani@danielbertalan.dev>
Link: https://lore.kernel.org/r/20230414180034.63914-1-dani@danielbertalan.dev
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>