ARM: zynq: remove TTC early mapping

Now that the TTC driver has proper support for DT bindings, it is not
necessary for the registers to be mapped early.  They will be mapped
during clock initialization using of_iomap().  Remove the early mapping.

In addition, remove the extraneous zynq_soc.h include from the timer
driver.

Signed-off-by: Josh Cartwright <josh.cartwright@ni.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>