cortex-a9: Remove cpu cache properties

Based on this thread
https://lkml.org/lkml/2013/11/13/111

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
zynq: Add 'clock-latency' property

Specify the 'clock-latency' property to avoid certain
cpufreq governors from refusing to work with
the following error:
ondemand governor failed, too long transition latency of HW,
fallback to performance governor

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
ps7_i2c: Remove i2c-clk generation

Signed-off-by: Michal Simek <michal.simek@xilinx.com>