drivers/clock_control: stm32h7: Add support for CKPER clock mux

Add support for CKPER clock mux.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

drivers/clock_control/clock_stm32_ll_h7.c

@@ -327,6 +327,7 @@ static int enabled_clock(uint32_t src_clk)
 {
 
 	if ((src_clk == STM32_SRC_SYSCLK) ||
+	    ((src_clk == STM32_SRC_CKPER) && IS_ENABLED(STM32_CKPER_ENABLED)) ||
 	    ((src_clk == STM32_SRC_HSE) && IS_ENABLED(STM32_HSE_ENABLED)) ||
 	    ((src_clk == STM32_SRC_HSI_KER) && IS_ENABLED(STM32_HSI_ENABLED)) ||
 	    ((src_clk == STM32_SRC_CSI_KER) && IS_ENABLED(STM32_CSI_ENABLED)) ||
@@ -476,6 +477,11 @@ static int stm32_clock_control_get_subsys_rate(const struct device *clock,
 	case STM32_SRC_SYSCLK:
 		*rate = get_hclk_frequency();
 		break;
+#if defined(STM32_CKPER_ENABLED)
+	case STM32_SRC_CKPER:
+		*rate = LL_RCC_GetCLKPClockFreq(LL_RCC_CLKP_CLKSOURCE);
+		break;
+#endif /* STM32_CKPER_ENABLED */
 #if defined(STM32_HSE_ENABLED)
 	case STM32_SRC_HSE:
 		*rate = STM32_HSE_FREQ;