Add Zhaoxin I2C controller driver. It provides the access to the i2c
busses, which connects to the touchpad, eeprom, I2S, etc.

Zhaoxin I2C controller has two separate busses, so may accommodate up
to two I2C adapters. Those adapters are listed in the ACPI namespace
with the IIC1D17 HID, and probed by a platform driver.

The driver works with IRQ mode, and supports basic I2C features. Flags
I2C_AQ_NO_ZERO_LEN and I2C_AQ_COMB_WRITE_THEN_READ are used to limit
the unsupported access.
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Hu <hanshu-oc@zhaoxin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>