tests: kernel/sleep: exclude npcx platforms from the test

According the specification, in extreme cases, the deviation of the APB
clock and LFCLK clock can reach up to +/-1% (+/- 10ms).
Therefore, exclude npcx platforms from the test because it required 1ms
accuracy.

fixes: #66185

Signed-off-by: Arkadiusz Cholewinski <[email protected]>

Author: gbarkadiusz

tests/kernel/sleep/testcase.yaml

@@ -13,5 +13,9 @@ tests:
       - kernel
       - sleep
       - libc
+    platform_exclude:
+      - npcx4m8f_evb
+      - npcx7m6fb_evb
+      - npcx9m6f_evb
     extra_configs:
       - CONFIG_MINIMAL_LIBC=y