tests: kernel: timer: timer_api: Fix test_timer_period_0
tests: kernel: timer: timer_api: Fix test_timer_period_0

This test was not waiting long enough to ensure one-shot behavior.

Signed-off-by: Eric Johnson <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@liveathos.com>

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