[nrf fromlist] drivers: timer: nrf_grtc: Move GRTC initialization to early init

GRTC is used by the logger, so it must be initialized
as early as possible. On the other hand, clock requests
are allowed once the clock control API has been initialized.
This PR introduces a two-stage GRTC initialization to meet
these requirements.

Upstream PR #: 96837

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk

drivers/timer/nrf_grtc_timer.c

@@ -517,6 +517,11 @@ static int sys_clock_driver_init(void)
 		system_timeout_set_relative(CYC_PER_TICK);
 	}
 
+	return 0;
+}
+
+static int grtc_post_init(void)
+{
 #if defined(CONFIG_CLOCK_CONTROL_NRF)
 	static const enum nrf_lfclk_start_mode mode =
 		IS_ENABLED(CONFIG_SYSTEM_CLOCK_NO_WAIT)
@@ -590,5 +595,6 @@ int nrf_grtc_timer_clock_driver_init(void)
 	return sys_clock_driver_init();
 }
 #else
-SYS_INIT(sys_clock_driver_init, PRE_KERNEL_2, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);
+SYS_INIT(sys_clock_driver_init, EARLY, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);
+SYS_INIT(grtc_post_init, PRE_KERNEL_2, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);
 #endif