[nrf fromtree] tests: kernel: timer: behavior: Adjustments for NRF54H20 PPR

Adjusting CONFIG_SYS_CLOCK_TICKS_PER_SEC as core is to slow too run
the test with the default system clock frequency.

Signed-off-by: Paweł Pelikan <[email protected]>
(cherry picked from commit fddce23)

Author: ppelikan-nordic

tests/kernel/timer/timer_behavior/boards/nrf54h20dk_nrf54h20_cpuppr_xip.conf

@@ -0,0 +1 @@
+CONFIG_SYS_CLOCK_TICKS_PER_SEC=3906