[DM/FEATURE] make SoC Kconfig import easy

Open Kconfig will not fail if using osource,
This way can make SoC Kconfig to DM easy.

Link: ecb89b1370

Signed-off-by: GuEe-GUI <2991707448@qq.com>

components/drivers/Kconfig.dm

@@ -1,5 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-#
-# This a empty file for SoC DM Kconfig
-#
-comment "SoC Device Drivers"

components/drivers/clk/Kconfig

@@ -5,5 +5,5 @@ menuconfig RT_USING_CLK
     default y
 
 if RT_USING_CLK
-    source "$(RTT_DIR)/components/drivers/$(SOC_DM_CLK_DIR)/Kconfig.dm"
+    osource "$(SOC_DM_CLK_DIR)/Kconfig"
 endif