hw/i2c: Implement NPCM7XX SMBus Module FIFO Mode

hw/i2c: Implement NPCM7XX SMBus Module FIFO Mode

This patch implements the FIFO mode of the SMBus module. In FIFO, the
user transmits or receives at most 16 bytes at a time. The FIFO mode
allows the module to transmit large amount of data faster than single
byte mode.

Since we only added the device in a patch that is only a few commits
away in the same patch set. We do not increase the VMstate version
number in this special case.

Reviewed-by: Doug Evans<dje@google.com>
Reviewed-by: Tyrong Ting<kfting@nuvoton.com>
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Corey Minyard <cminyard@mvista.com>
Message-id: 20210210220426.3577804-6-wuhaotsh@google.com
Acked-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>