clk: zynqmp: Warn user if clock user are more than allowed

clk: zynqmp: Warn user if clock user are more than allowed

Warn user if clock is used by more than allowed devices.
This check is done by firmware and returns respective
error code. Upon receiving error code for excessive user,
warn user for the same.

This change is done to restrict VPLL use count. It is
assumed that VPLL is used by one user only.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Link: https://lkml.kernel.org/r/1575527759-26452-4-git-send-email-rajan.vaja@xilinx.com
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>