Turn on SoC pull-ups on I2C pins, since there are no discrete pull-up
resistors on the bus.
Increase clock to 400 kHz. Both chips on the bus support 400 kHz. I
tested the ISL28022 at 4,000 reads/sec and didn't see any garbled output
or bus hangs, even with SoC drive strength reduced to 2 for the test.
Signed-off-by: Ryan Salsbury <ryanrs@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/15334
Signed-off-by: Robert Marko <robimarko@gmail.com>