Why I did it
There is rare condition, emc2305 hold SMBus and cause SMBus completion wait timed out.
How I did it
Enable EMC2305 SMBus timeout feature, 30ms period of inactivity will reset the interface.
How to verify it
Use 'i2cget -y -f 23 0x4d 0x20 b' to read EMC2305 configuration register and check DIS_TO bit not set.
Signed-off-by: Eric Zhu <erzhu@celestica.com>