microblaze: timer: Do not initialized system timer twice
microblaze: timer: Do not initialized system timer twice

Only one system timer can be setup.
Do not initialize more system timers.

Signed-off-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs