boards/smartl-c906: enable hrtimer

  Enable hrtimer support on the smartl-c906 board so that CI can build
  and exercise the hrtimer subsystem.

Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>

Author: wangchdo

boards/risc-v/c906/smartl-c906/configs/sotest/defconfig

@@ -27,6 +27,7 @@ CONFIG_EXAMPLES_HELLO=y
 CONFIG_EXAMPLES_SOTEST=y
 CONFIG_FS_PROCFS=y
 CONFIG_FS_ROMFS=y
+CONFIG_HRTIMER=y
 CONFIG_IDLETHREAD_STACKSIZE=2048
 CONFIG_INIT_ENTRYPOINT="nsh_main"
 CONFIG_INIT_STACKSIZE=3072
@@ -59,6 +60,7 @@ CONFIG_START_DAY=7
 CONFIG_START_MONTH=3
 CONFIG_START_YEAR=2021
 CONFIG_SYSTEM_NSH=y
+CONFIG_SYSTEM_TIME64=y
 CONFIG_TASK_NAME_SIZE=20
 CONFIG_TESTING_GETPRIME=y
 CONFIG_TESTING_OSTEST=y