i2c-ali1535: enable SPARC support

The i2c-ali1535 driver doesn't work on SPARC, because it assumes that
ioport address are 16-bit wide (address stored in an unsigned short).
But on SPARC arch, ioports are mapped in memory and so must be stored
in an unsigned long.

Use pci_resource_start for getting IOMEM base address, then read the
SMBBA of the i2c bus and use these together for I/O access.

I would like to thank Jean DELVARE for reviewing my patch.

Signed-off-by: LABBE Corentin <corentin.labbe@geomatys.fr>
Signed-off-by: Jean Delvare <khali@linux-fr.org>