tests: posix: common: clock: remove poorly conditioned tests
tests: posix: common: clock: remove poorly conditioned tests

The test assumed initial equality between CLOCK_MONOTONIC and
CLOCK_REALTIME and also assumed coarse granularity for each clock.
Neither of those assumptions are solid.

Furthermore, the test failed on multiple vendor boards which caused
some concern.

Remove the poorly conditioned tests and remove some comments
/ printks.

Fixes #35703

Signed-off-by: Christopher Friedt <76f728c1c3997bf5bfe7e9261eff720c92409a2f@gmail.com>

zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr