drivers: timer: stm32: Clean up related to STM32_LPTIM_CLOCK

Now that STM32_LPTIM_CLOCK choice symbol is defined from device tree,
remove the prompt which was defining it as a user selectable entry.

Remove the warning related to possible symbol misalignment with
device tree setting.

Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>

drivers/timer/Kconfig.stm32_lptim

@@ -35,7 +35,7 @@ config STM32_LPTIM_CLOCK_LSE
 endchoice
 
 config STM32_LPTIM_CLOCK
-	int "LPTIM clock value"
+	int
 	default 32768 if STM32_LPTIM_CLOCK_LSE
 	default 32000 if STM32_LPTIM_CLOCK_LSI
 

drivers/timer/stm32_lptim_timer.c

@@ -66,22 +66,6 @@ static uint32_t lptim_clock_freq = CONFIG_STM32_LPTIM_CLOCK;
 /* The prescaler given by the DTS and to apply to the lptim_clock_freq */
 static uint32_t lptim_clock_presc = DT_PROP(DT_DRV_INST(0), st_prescaler);
 
-#if (CONFIG_STM32_LPTIM_CLOCK_LSI)
-
-/* Kconfig defines the clock source as LSI : check coherency with DTS */
-#if (DT_INST_CLOCKS_CELL_BY_IDX(0, 1, bus) != STM32_SRC_LSI)
-#warning CONFIG_STM32_LPTIM_CLOCK_LSI requires STM32_SRC_LSI defined as LPTIM domain clock
-#endif /* STM32_SRC_LSI */
-
-#elif (CONFIG_STM32_LPTIM_CLOCK_LSE)
-
-/* Kconfig defines the clock source as LSE : check coherency with DTS */
-#if (DT_INST_CLOCKS_CELL_BY_IDX(0, 1, bus) != STM32_SRC_LSE)
-#warning CONFIG_STM32_LPTIM_CLOCK_LSE requires STM32_SRC_LSE defined as LPTIM domain clock
-#endif /* STM32_SRC_LSE */
-
-#endif /* CONFIG_STM32_LPTIM_CLOCK_LSI */
-
 /* Minimum nb of clock cycles to have to set autoreload register correctly */
 #define LPTIM_GUARD_VALUE 2