adi-hdmi-load: Omit AXI IIC controller driver

The miami boards don't need the AXI I2C controller for HDMI, so remove
it from the module list.
miami-xilinx-sdk: Reduce VDMA clocks from 150 to 100MHz

Experiments show that the minimum clock is way below 100MHz, the VDMA
retrieves 2 pixels per clock, for a single full-hd stream it would
need only 60MHz. To support two displays, and to allow for extra
headroom, 100MHz is a good balance.

The VDMA clock is driven by FCLK1. It could be routed to FCLK0 to
accomplish the same effect (and save on clock domains).
linux-topic: Update to support dynamic audio clocking

The cdce925 can now be used to provide the audio clock for the HDMI SPDIF
output, so that audio can be played at 44100Hz sampling rates.