arm: zynq: Invalidate L1 in secondary boot

During boot, Linux initiates a clean-invalidate operation only, resulting
in faulty data to be written to the memory system during resume.
Therefore invalidate the L1 in the secondary boot path to avoid these
issues.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>