kernel: fix k_sleep in no multi-threading mode

[KushnerovMikhail]

Fix k_sleep implementation for no multi-threading mode.

Absolute value of timeout expiration was fed to the k_busy_wait() function instead of delta value. That caused bug like incrementing of sleep time in geometric progression (while actual function argument is constant) during program running.

You can check it by simple program with CONFIG_MULTITHREADING=n option:

#include <zephyr/kernel.h>

int main (void)
{
	uint32_t new_ticks = 0;
	uint32_t old_ticks = sys_clock_tick_get_32();

	while (1) {
		k_sleep(K_MSEC(1000));
		new_ticks = sys_clock_tick_get_32();
		printf("%u\n", new_ticks - old_ticks);
		old_ticks = new_ticks;
	}

	return 0;
}

Output from qemu_riscv64
Before fix:
100
200
400
800
...

After fix:
100
100
100
100
...

[peter-mitsis]

If we have already passed the absolute point in time (Z_TICKS_ABS(ticks) < sys_clock_tick_get_32()), we should set ticks_to_wait to 0, otherwise we are waiting when we should not be waiting.

[KushnerovMikhail]

Thanks for the comment. Fixed it