arm64: zynqmp: Setup clock for DP and DPDMA

Clocks are coming from shared HW design where these frequencies should be
aligned with PLL setup.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/04454c50d0d13e450976942085d763ab5aa38f98.1645629459.git.michal.simek@xilinx.com