[bsp][cvitek] add rtc driver (#8586)

bsp/cvitek/c906_little/board/Kconfig

@@ -86,4 +86,9 @@ menu "General Drivers Configuration"
             bool "Enable PWM 3"
             default n
         endif
+
+    config BSP_USING_RTC
+        bool "Enable RTC"
+        select RT_USING_RTC
+        default n
 endmenu

bsp/cvitek/drivers/SConscript

@@ -26,6 +26,9 @@ if GetDepend('BSP_USING_PWM'):
     CPPPATH += [cwd + r'/cv1800b/pwm']
 CPPDEFINES += ['-DCONFIG_64BIT']
 
+if GetDepend('BSP_USING_RTC'):
+    src += ['drv_rtc.c']
+
 group = DefineGroup('drivers', src, depend = [''], CPPDEFINES = CPPDEFINES, CPPPATH = CPPPATH)
 
 Return('group')