platform-x86: intel_mid_thermal: convert to use Intel MSIC API

Intel MSIC MFD driver provides common register access interface to the
devices in the MSIC die so we use that instead of SCU IPC.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>