i2c: mlxcpld: Fix criteria for frequency setting

Value for getting frequency capability wrongly has been taken from
register offset instead of register value.

Fixes: 66b0c2846ba8 ("i2c: mlxcpld: Add support for I2C bus frequency setting")
Signed-off-by: Vadim Pasternak <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/busses/i2c-mlxcpld.c

···
 		return err;
 
 	/* Set frequency only if it is not 100KHz, which is default. */
-	switch ((data->reg & data->mask) >> data->bit) {
+	switch ((regval & data->mask) >> data->bit) {
 	case MLXCPLD_I2C_FREQ_1000KHZ:
 		freq = MLXCPLD_I2C_FREQ_1000KHZ_SET;
 		break;