tests: kernel: timer tests for kit_psc3m5_evk board

Adding overlays for Infineon kit_psc3m5_evk board to kernel/common,
kernel/timer/timer_error_case and kernel/timer/timer_api tests
when run in secure mode.  These tests require more memory than
the board assigns to secure mode by default.

Signed-off-by: John Batch <john.batch@infineon.com>