[bsp][stm32] fix the CONFIG_RT_USING_CLOCK_TIME issue.

Author: BernardXiong

bsp/stm32/stm32l496-st-nucleo/.ci/attachconfig/ci.attachconfig.yml

@@ -64,7 +64,7 @@ pkg.kernel_en_sample:
     - CONFIG_KERNEL_SAMPLES_USING_PRODUCER_CONSUMER=y
 pkg.peripheral.sample:
   kconfig:
-    - CONFIG_RT_USING_CLOCK_TIME
+    - CONFIG_RT_USING_CLOCK_TIME=y
     - CONFIG_PKG_USING_PERIPHERAL_SAMPLES=y
     - CONFIG_PERIPHERAL_SAMPLES_USING_ADC=y
     - CONFIG_PERIPHERAL_SAMPLES_USING_HWTIMER=y