USB: sisusbvga: Change port variable from signed to unsigned

Change a bunch of arguments of wrapper functions which pass signed
integer to an unsigned integer which might cause undefined behaviors
when sign integer overflow.

Signed-off-by: Changming Liu <liu.changm@northeastern.edu>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/BL0PR06MB45482D71EA822D75A0E60A2EE5D50@BL0PR06MB4548.namprd06.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>