i2c: designware: Fix RX FIFO depth define on Wangxun 10Gb NIC

I believe RX FIFO depth define 0 is incorrect on Wangxun 10Gb NIC. It
must be at least 1 since code is able to read received data from the
DW_IC_DATA_CMD register.

For now this define is irrelevant since the txgbe_i2c_dw_xfer_quirk()
doesn't use the rx_fifo_depth member variable of struct dw_i2c_dev but
is needed when converting code into generic polling mode implementation.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>