driver: clock_control: renesas_ra: Use pclkblock's clock src defaultly

When omitting the clk_src definition in a child node of a pclkblock,
it uses the source of the parent node.

Signed-off-by: TOKITA Hiroshi <[email protected]>

Author: soburi

drivers/clock_control/clock_control_renesas_ra_cgc.c

@@ -90,7 +90,9 @@ static const struct clock_control_driver_api clock_control_reneas_ra_api = {
 #define INIT_PCLK(node_id)                                                                         \
 	IF_ENABLED(DT_NODE_HAS_COMPAT(node_id, renesas_ra_cgc_pclk),                               \
 		   (static const struct clock_control_ra_pclk_cfg node_id##_cfg =                  \
-			    {.clk_src = DT_PROP_OR(node_id, clk_src, RA_CLOCK_SOURCE_DISABLE),     \
+			    {.clk_src = DT_PROP_OR(node_id, clk_src,                               \
+						   DT_PROP_OR(DT_PARENT(node_id), sysclock_src,    \
+							      RA_CLOCK_SOURCE_DISABLE)),           \
 			     .clk_div = DT_PROP_OR(node_id, clk_div, RA_SYS_CLOCK_DIV_1)};         \
 		    DEVICE_DT_DEFINE(node_id, &clock_control_ra_init_pclk, NULL, NULL,             \
 				     &node_id##_cfg, PRE_KERNEL_1,                                 \