i2c: i801: Fix Failed to allocate irq -2147483648 error

On Apollo Lake devices the BIOS does not set up IRQ routing for the i801
SMBUS controller IRQ, so we end up with dev->irq set to IRQ_NOTCONNECTED.

Detect this and do not try to use the irq in this case silencing:
i801_smbus 0000:00:1f.1: Failed to allocate irq -2147483648: -107

Cc: stable@vger.kernel.org
BugLink: https://communities.intel.com/thread/114759


Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>