i2c: mediatek: Fix generic definitions for bus frequency

The max frequency of mediatek i2c controller driver is
I2C_MAX_HIGH_SPEED_MODE_FREQ, not I2C_MAX_FAST_MODE_PLUS_FREQ.
Fix it.

Fixes: 90224e64 ("i2c: drivers: Use generic definitions for bus frequencies")
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>