i2c: mediatek: modify threshold passed to i2c_get_dma_safe_msg_buf()

i2c: mediatek: modify threshold passed to i2c_get_dma_safe_msg_buf()

commit bc1a7f75c85e226e82f183d30d75c357f92b6029 upstream.

DMA with zero-length transfers doesn't make sense and this HW doesn't
support them at all, so increase the threshold.

Fixes: fc66b39fe36a ("i2c: mediatek: Use DMA safe buffers for i2c transactions")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[wsa: reworded commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>