I2C: i2c-piix4: Add Broadcom HT-1000 support

Add Broadcom HT-1000 south bridge's PCI ID to i2c-piix driver. Note
that at least on Supermicro H8SSL it uses non-standard SMBHSTCFG = 3
and standard values like 0 or 9 causes hangup.

Signed-off-by: Martin Devera <devik@cdi.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>