mfd: intel-lpss: Provide an SSP type to the SPI driver

The SPI driver wants to know the exact type of the controller.
Provide this information to it. This is a complementary part to
the previously updated intel-lpss-acpi.c.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220702211903.9093-1-andriy.shevchenko@linux.intel.com