soc/intel/cannonlake: Correct the data type of serial_io_dev

Change-Id: Id974a4bb84b7d5caddece04f93bf4e830d15b576
Signed-off-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34466
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/cannonlake/fsp_params.c

@@ -26,7 +26,7 @@
 
 #include "chip.h"
 
-static const int serial_io_dev[] = {
+static const pci_devfn_t serial_io_dev[] = {
 	PCH_DEVFN_I2C0,
 	PCH_DEVFN_I2C1,
 	PCH_DEVFN_I2C2,