I2C: zynq: Reuse platform device ID as adapter number

Reusing pdev->id for the I2C adapter number allows to remove the
'bus-id' DT property.
Tegra, Omap use it.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
I2C: Convert 'i2c-clk' property to 'clock-frequency'

Align this driver more with other drivers by using the property
'clock-frequency' to specify the maximum I2C bus frequency.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
I2C: zynq: Refactor frequency adjustment policy

I2C allows frequencies in the range from 0 to 100 kHz in standard and up
to 400 kHz in fast operating mode. Adjust the logic handling frequencies
accordingly, to generate a clock within spec and the selected I2C
operating mode.

Reported-by: Yashu Gosain <yashug@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Yashu Gosain <yashug@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
ARM: zynq: defconfig: Enable UCD drivers

UCD9000 and UCD9200 devices are common on Zynq platforms. Enable the
hwmon drivers for those devices on default.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>