i2c: designware: Fix standard mode speed when configuring the slave mode

Code sets bit DW_IC_CON_SPEED_FAST (0x4) always when configuring the slave
mode. This results incorrect register value DW_IC_CON_SPEED_HIGH (0x6)
when OR'ed together with DW_IC_CON_SPEED_STD (0x2).

Remove this and let the code set the speed mode bits according to clock
frequency or default to fast mode.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-designware-platdrv.c

@@ -198,8 +198,7 @@ static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
 	dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
 
 	dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
-			 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED |
-			 DW_IC_CON_SPEED_FAST;
+			 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
 
 	dev->mode = DW_IC_SLAVE;