ACPI: LPSS: Advertise number of chip selects via property

Advertise number of chip selects via property for Intel Braswell.

Fixes: 620c803f ("ACPI: LPSS: Provide an SSP type to the driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_lpss.c

@@ -325,6 +325,7 @@ static const struct lpss_device_desc bsw_i2c_dev_desc = {
 
 static const struct property_entry bsw_spi_properties[] = {
 	PROPERTY_ENTRY_U32("intel,spi-pxa2xx-type", LPSS_BSW_SSP),
+	PROPERTY_ENTRY_U32("num-cs", 2),
 	{ }
 };