drivers: clk: Add ZynqMP clock driver

This patch adds CCF compliant clock driver for ZynqMP.
Clock driver queries supported clock information from
firmware and regiters pll and output clocks with CCF.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Tejas Patel <tejasp@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>